It's supposed to sync at said intervals then shut off Auto Sync. What happens is that it does sync..and even shut off...but then sometime afterward turn back on and stays on, defeating the purpose of periodic auto sync and saving battery.
Could be it's just buggy, but I don't quite see how it's supposed to know what time it is if a portion of the program doesn't run constantly. Seems like something would have to
make an app start. I know the time triggers it, but
how, if not for that being written into your app? (Although maybe the permissions would reveal if it was doing anything to the system settings that would handle the wakeup - I'm just guessing here, and don't know if that is possible).
If you're running a task killer, you might try disabling it. That sometimes solves problems with things not following correct schedules.
Edited to add: I finally got a good enough connection to check the permissions in the Market, and it DOES "rewrite sync settings" , which explains what was puzzling me. Sorry for the confusion.
Could you tell me what symptoms you see to indicate that it's "on"? If it's just that it appears in Settings/Applications, this does not necessarily mean an app is really running or using battery. If it's a notification bar icon or something like that, it sounds more like a bug, and perhaps the developer could help.