RH8 - Evolution disappeared?

Hi,

I switched to RH8 (from W2k) about 2 weeks ago and have had a mostly 
positive experience.

Last night, I tried installing two Gnome frontends to smbclient (Gnomba 
and Jags). Couldn't get either to work, but it was around this time that 
suddenly Evolution couldn't open a compose window. I shut it down and 
tried to restart it, but the binary is just gone. 'which evolution' 
doesn't find it. 'killev' is also gone.

Other symptoms: 

- no icons are on my desktop anymore (used to have 'start here', 'john's 
home', 'trash', and 'yahoo messenger')

- right clicking on my desktop no longer brings up a menu at all -- 
nothing happens

- my 'gedit' launcher doesn't work (looks like gedit is also gone - no 
such file or directory)

- I no longer get the nice Bluecurve graphical login screen. Instead I get 
an ugly Xfree86 login screen.


So I've hosed my system pretty well. Any ideas about where to start 
digging?

Thanks.

-John