I have same problem on Nexus S, has been happening since phone was upgraded to ICS.
I have tried all of the following.
Cleared Cache from Store
Deleted Google Synce'd account
Open Store re-registered account
-- Same Problem
Deleted and Updated Payment details
Cleared Cache from Store
Deleted Google Synce'd account
Open Store re-registered account
-- Same Problem
Deleted and Updated address details
Cleared Cache from Store
Deleted Google Synce'd account
Open Store re-registered account
-- Same Problem
Registered new Google account
Cleared Cache from Store
Deleted Google Synce'd account
Open Store re-registered account
-- Same Problem
All the above failed to resolve the issue. Haven't done a hard reset as don't really want to go through all that and lose data (texts), contacts and what not.
Can't install from on-line store via PC either as this seems to think my phone isn't registered.
Had no problems downloading anything before ICS was installed.
Can't install Free or Paid for apps, always get the same error "error while processing purchase"
Looked on countless sites and this has been happening on/off for over a year and Googles own help desk have been next to useless trying to resolve this particular problem.
Various people have had success with the above suggested fixes, but none have worked for me.
Help please.....
