I have reported this to Symantec support but thought I would post this to here as well.
On a number of machines users get the following message boxes pop up all with c:\program files\Symantec\ghost\ngctw32.exe in the title:
aiobuf::sync() position error
press ok then
Out-of-order producer completion
press ok then
IoDebugBreak
press ok then it loops round the last two messages until you either reboot or stop the client service. All the machines are HP (various models) and are Windows XP SP2
Any ideas?