I posted it in the general area but i rather post it here too, because it seems to be related to quickpwn.
Restored to 2.0.1 - got signal.
Restored to custom 2.0.1 Activated, Jailbroken - still have signal.
Updated to 2.1 - still got signal.
After jailbroken 2.1 with quickpwn - signal is gone.
So it seems that something that has to do with jailbroken 2.1 has that signal issue (maybe the info.plist file from bundles?)