Possibly - although a bad entry in the config file which slipped in at some point somehow is more likely.
If the issue reappears, please reopen the topic.

I deleted plasma-desktop-appletrc but the device notifier still continues to pop up when switching windows. It triggers for me consistently when I switch between konsole windows. Just upgraded to KDE 4.11.3 and the problem is still there. I am running gentoo linux.

I'm assuming you aren't the original poster. Please verify you don't have any unusual KWin rules which could be causing this behaviour - ideally just defaults.

For what it's worth, I have been upgrading this particular kde instance since the early 4s. It's certainly possible I have some legacy config line some place. It's mostly stock, just a few basic tweaks via the system configuration tool. Auto hide panel, change to plastik window decoration, oxygen, classic start menu. Not too exotic.

I set up a another account on my system and cannot reproduce the problem from the few minutes I tested it, but I don't have all the same apps running there either.

I then tried deleting kwin* from share/config and at first that seems to fix the problem in my principal account. I can't initiate the behavior switching windows, lowering and raising them, however, once I start using my desktop at some point during the day, the device notifier begins popping up every time I switch windows. My suspicion is that it has something to do with PSI and Chrome, but I can't be sure. Should I be concentrating my efforts in kwinrc or someplace else? I am can't be sure a clean wipe of .kde4 would fix it either, since the problem begins popping up after some time of usage.

Okay. If eliminating the Plasma and KWin configuration files doesn't eliminate the issue, then i'm not sure what could be causing this - as they're the only two applications which should be able to cause this in theory. I'm assuming that once the issue begins, it is consistently and fully reproducible until you logout and back in again?

That is correct. Worked for a time, then reappeared at some point during the day and then would not go away until I logged out. I worked with my test account changing its configuration setting to match my main account and I was unable to reproduce the behavior. I don't actually fully understand how all the plasma and kwin config files interact, so sorry I'm not more help. In the end I just deleted everything, and reconfigured my desktop. It's been a few days and the problem has not reappeared. I really wanted to get to the bottom of the behavior, but alas, it will just have to be categorized as some legacy bit from an older kde4 version.

Okay. I've marked the topic as solved for now - if the issue reappears we can investigate further into what caused this, as it is extremely unusual. My next suspicion would have been a keyboard shortcut which was being inadvertently triggered.

I suppose it's possible, but I checked that - alt-tab triggered it, but more often it seemed to be initially triggered by raising the chat window of PSI. I can't be sure, because it happened on a mouse raise of a konsole window too. But, sure, I consider this solved and chalk it up to something outside of normal on my end. Googling around, there only seem to have been myself and one other user (both of us on Gentoo) that have had this issue.

I've been hitting this bug for half a year or so. Unfortunately it still occurs in 4.12.1 on my gentoo machine.
I hoped that it would get fixed in 4.11, 4.12,.. but since it's still there i decided too see if there are other people with this bug and here I am

I guess it would be reasonable to fill a bug for this, right?

Yes, I'm still getting the problem too (I started this topic originally.)

I'm not able to give more information than I have and I've tried so many different combinations of things, none of which have worked permanently.

It seems that is the only solution proffered so far - that somehow some configuration changes over th years within KDE have caused this strange behaviour.
Frankly the suggestion of deleting the .kde4 folder is not acceptable to me - I have several years of tweaking and configuration there - there is no feasible way (I can see) of documenting all of those e.g my mime configurations, apps associated with file extension, menu tweaks, keyboard shjortcuts, .desktop files etc. etc. etc.

So now I just continue to suffer - my current workflow is to hide the Device Notifier from the System Tray settings until I need ti use it. Re-ebale it when I DO need it and then wait for it to start misbehaving nd then Hide it again.

It's really a pain using removable devices, but I can understand how not starting from a fresh configuration causes trouble tracking down the problem to try and fix it.

I would suggest someone file a bug report. I will note that I have previously seen cases where, for unknown reasons, certain applications would reproducibly trigger this behaviour - Pidgin in one case.

FYI - it's already been reported as a bug - 328788

I can confirm this bug.

This happen with any windows which are grouped together (Qt Designer, QGIS, ...)

I could confirm this behavior too.

Its really annoying:
First test: If i start two dolphin instances i could switch between them, without any notifier popup. If i move one dolphin window to another workplace and switch between them, the device notifier pops up.
Second test: If i start two dolphin instances and switch between them, the device notifier pops up, regardless of switching one dolphin window to another workplace :-S

The notifier pops only up, if i switch the windows with the window panel, not with "alt-tab".

I do have two opera-windows on different workplaces, but switching between them do not fire the notifier popup.

Version: kde 4.14.2 on arch-linux

Confirm this issue on Kubuntu 14.04 with KDE 4.13.3. It is reproducable only when I switch between programs via click on panel, via alt-tab all works well.