Version: (using Devel) OS: Linux Installed from: Compiled sources If I adjust the size, making it thicker or thinner, it is only transparent at certain sizes. For the other sizes it just turns blue. If the panel is at the bottom of the screen it stays transparent for all sizes. This is with the 4.2 beta1 binaries from kubuntu using the default plasma theme.
sounds like the pixmap cache not being invalidated when composite is turned on. try changing the Plasma theme, then switch back to the theme you were on and see if that helps the symptom go away.
If I change themes and back again it does indeed make it transparent and afterwards I seem to be able to resize it without the issue occuring again
ok, so indeed it was the pixmap cache not being invalidated when the composition setting changed.
*** Bug 178234 has been marked as a duplicate of this bug. ***
Similar problem here with KDE 4.2.0 (from Kubuntu 8.10 packages). My panel (full width at the bottom of the screen) sometimes becomes solid blue when logging in KDE (it was transparent when I previously logged out). All other desktop effects are still available when this occurs. I used to solve the issue by removing the panel and creating a new one from scratch. As suggested by Aaron in comment #1, changing the Plasma theme and switching back to Oxygen theme also restores the panel transparency.
I can confirm this bug. Changing from Oxygen to another theme didn't respect the new theme's panel background or enable transparency unless I shrank the panel width. Going back to full width changed panel background back to opaque blue from Oxygen theme. Switching back to Oxygen and then to the new theme again seemed to fix this again.
I cannot reproduce the bug anymore (I remember it some weeks ago). I'm using current trunk r959285.
I can't reproduce on r961515.