Help Nexus One won't update

[Phake]

Hello

My Nexus One will not update. It went fine till 2.2.1 and stopped right there. The OTA is not coming and when I try the manual update I get

E:failed to verify whole-file signature
E:signature verification failed
Installation aborted.

error. This happens with multiple different files. My phone is not rooted. I tried factory data reset.
The manual *#*#checkin#*#* does nothing. I get "checkin succeeded ever time but there is no update available anyway.

I really could use some help

Phake

 

[Rusty]

Let me guess, bought it from a carrier?