My htc hero can't seem to keep apps running in the background, save for a few, such as the engadget app. when I press home from the internet browser or the PDF viewer and try to get back into the application, the internet browser will resend info to get the page I was on back and the PDF viewer will restart just like the browser and end up in a PDF file I wasn't in before. It seems that the applications restart themselves when I get out of them. Also, I just downloaded the 2.1 update for TELUS, so I'm not sure if thats to blame.