Quick question. Do I need to have all the RIM themes installed or just the one I'm using?

You only need the one that is currently active.

Wirelessly posted

I don't know if this is true in other OS versions or not, but it would seems in 4.5.0.42 Zen must also be installed.

I think it may be some kind of java console. With that theme uninstalled I lost all of my home screen icons. They reverted to some kind of wire frame default. Also I wasn't able to open media and my computer stopped recognising my BB as a removable device.

If you uninstall a particular default theme, you cannot install any themes of its type.

I know on my pearl, I have to keep dimension zen, everything else can be deleted...i only have zen, today plus and the vodafone theme left...