the system gives this error:
Error: installLocation has no properties
Source File: file:///usr/lib/firefox/components/nsExtensionManager.js
Line: 3938

any idea? i believe it should be a common problem
i am using ubuntu 8.04 AMD64

btw, another problem is i installed XFCE in ubuntu(gnome)
it gives the xfce loading interface but when i login, it is still gnome
any idea?

thanks alot!