Sometimes when I try to install a program, I get a message on the PDA that the "Install of was unsuccessful"
How do I troubleshoot this?

Currently I'm trying to install Avantgo Client

I've got an UtStar VX6700 (Audiovox)  and I've tried installing both the WM5.0 and WM5.0 Smartphone versions of Avantgo, and the beta versions of both. 

I've had the problem with other programs as well (the Activated Version of MS Reader). 

I've tried both main memory and the storage card (1GB), tried reseting the device before installing it (per AvantGo's website) and nothing seems to work.