With the release of Microsoft Dynamics GP 2010 SP3, MSFT GP development team has fixed one of the nagging bugs which got introduced in Microsoft Dynamics GP 2010 R2.
The following posts would explain what exactly that issue is:
Error When Switching Back To Microsoft Dynamics GP From Report Writer (Ian Grieve)
Unhandled script exception: Illegal address for field ‘[Not Found]’ in script ‘Unregister_Triggers’ (Mariano Gomez)
Rest assured that this bug is now fixed with the release of Gp 2010 SP3.