Have you tried a factory reset?
If you have auto-sync enabled, try disabling it.
Worked for me.
Settings --> Applications -->All--> Download Manager --> Clear Data/Cache
Try that............Google is your friend ;o)
What else have you tried?
I have the same issue. After doing an upgrade that it was bugging me to do, I get this message popping up every 5 seconds or so. I have no idea what it means, I can't find the process in the app manager. When I disable SYNC, the issues stops... but what does disabling SYNC do? Isn't that a pretty important function?
There must be some way to fix this issue without defeaturing the phone