Is there a simple way to remember panel configurations for different monitor settings?

I'm having myself a dual-monitor setup with my laptop, and I have panels on both monitors. When I disconnect the other monitor, all panels get thrown to my laptop monitor — and when I reconnect the monitor, all panels stay on my laptop monitor (which is not desired behavior).

I've used to have a script that killed plasma-desktop, switched configurations and re-launched [plasma-desktop], but since last Kubuntu update this method often crashes about everything that can be crashed (not to mention that method refuses to start before KDM launches).

Can you please explain which processes in particular are crashing? They shouldn't be crashing in general.
Also, how were you "killing" Plasma Desktop? Were you using kquitapp or kill?

I'm using kquitapp to kill the process. (Whole script if interested: http://pastebin.com/FF6UJNVk, pretty much unchanged since written.)

I don't know which processes in particular are crashing, but when plasma doesn't come up in less than 30 seconds (normally it takes ~15 seconds from launching script to the point when everything is up and running) and you can't even ctrl-alt-f1 yourself to TTY1 and login there, something has gotten very wrong. In some other times, I'd find KWin either crashed or not working (I assume by the lack of Window frames) and in some cases it would be just plasma refusing to start.

Plasma crashes on exit here, i pkill -9 it to prevent it from autolaunching on the sigsegv.
To figure what is "everything" that crashes, dr. konqui might be a good hint - also esp. on "why". That's not necessarily the same reason.
If you don't even get the crash dialog, sth. should be really screwed in your installation.