When I boot into Kubuntu, always see at the panel tray that wireless networks are enabled. To be safe (and feel safe), I used to unceck it (disable). But next time I will find it checked again.
(I do not use wireless networks.)

It appears that this is not currently a setting that is persistent. Note that KNetworkManager will never connect to a network unless you instruct it to.

Try right-clicking the wireless symbol in the tray, select "Manage Connections," select "Wireless" tab, select the wireless connection, select "Edit" on the right side panel, deselect "Connect Automatically," then OK and Apply back out as necessary.

I would think that would do it.

GregBrannon wrote:Try right-clicking the wireless symbol in the tray, select "Manage Connections," select "Wireless" tab, select the wireless connection,

My "Wireless" tab is grayed out. (disabled)

(Does it mean that I can feel very safe? Will remain grayed? Will ever be there any connenction?)

(Then, the "wireless connections are enabled" flag is false? Just to ignore? (hm.. dangerous a bit))

If "Wireless connections are enabled" is false, then that means that "Wireless communications are disabled" which is what you desire I believe.