I am on htc tattoo, android version 1.6. I open 3xc and it registers fine and makes very good calls. Then I exit 3xc to conserve battery. However, the system continues to use a lot of battery power for some reason. The only way that I've found to return to normal battery usage is to turn the phone off and on. Is there some bug with 3xc that keeps using the internet even after closing the app? I had the same problem with sipagent as well. I've narrowed it down to these 2 apps only, I have nothing else running. Without opening 3xc the battery usage is at least 5 times lower.