Version:           3.4.92 (using KDE 3.4.92 (beta2, >= 20051010), compiled sources)
Compiler:          gcc version 3.3.6 (Gentoo 3.3.6, ssp-3.3.6-1.0, pie-8.7.8)
OS:                Linux (i686) release 2.6.12-gentoo-r6

After setting kicker to have a transparent background, whenever I switch virtual desktops, the transparency disappears, showing the  normal kicker background color instead.  The only way to get the transparency back is to hide the panel with the hide button, and then show it again.  However, if the kicker is set to auto-hide, then it does not show transparency when a mouseover raises it.

Possibly duplicates one or more existing reports:
60996: I mention this old one because that report cites that Desktop 2 seemed to behave properly.  I also noticed this for a time, but during my investigation, Desk 2 lost its "magic" somehow, and now behaves like the other virtual desktops...

110569: Description sounds very similar to what I am seeing.  However, if there's really nothing to be done to fix this for 3.x, then I would suggest disabling panel transparency for 3.5, because it doesn't really work at all if there are virtual desktops.  

A suggestion: somehow, the code that handles bringing the panel back after having been (manually) hidden restores transparency to the panel.  If the responsible code could be identified, wouldn't it be relatively easy to add it to the auto-hide mouseover and desktop switching code as well?

114120: this report is similar, but I am using the same wallpaper image in all 4 desktops...

How to reproduce: Make kicker transparent, then simply switch virtual desktops by clicking on the "Desktop Preview & Pager" applet, or using Ctrl+TAB

Expected behavior: Kicker panel maintains transparency when switching virtual desktops or when using auto-hide.  I swear this worked in 3.4.x...