Are you logging the results or displaying the error codes to the screen to see what is happening? And/Or do you see the logon script cmd box appear during this profile creation that you mention?

Are you running a Startup Script or Logon Script?

When the printers fail to install, do the mapped drives fail as well?

I can't say I have seen this though. I do have Wait for Network policy, Run logon scripts synchronously policy and use a traditional Logon Script for Mapping Drives and adding Printers.