I have kinda the same problem going on except everything on all of my home screens disappear for up to 30 seconds whenever I back out of an app or hit the home button and its happening more and more, I use to LOVE my phone but this is starting to get ridiculous and really pisses me off when I'm trying to use my phone for work and I have to sit there waiting for it, looking like an *****.
Completely stock, no app/task killers
I think the problem is related to the amount of free memory. When you exit out of a program and go back to the home screen and it has to re-draw the home screen it is usually due to the free RAM at the time.
Too many open apps.
The Charge only has about 324MB of RAM which is pretty low for this type of device. If you clear the memory, run your app, and exit out, I bet it goes better.
Yes, I agree this is a hassle, however, it seems to work for me.