Crash on one Exchange Server when Perm Deleting more than about 3,000 Messages

[dbisping]

Its the only system I have seen it on, it happens if I try and Perm delete more than say about 3,000 in one go,, lower that number and the delete works, error attached, might be unrelated, but we are unable to get a retention policy to kick in for these Public Folders, that's why we are using MFCMapi to delete the messages