Incremental Backup Dies in 10d SP4

Backup job dies when nearly complete, always at the same server. Reinstalled agent on that server, same problem. Event log shows:

Faulting application bengine.exe, version 10.1.5629.44, faulting module beclass.dll, version 10.1.5629.23, fault address 0x00032de7.

I end up having to restart the BE services. The other interesting issue is that the backup shows a valid size but no catalog is created. If I try to manually create a catalog it fails with error e00084ca.

Any thoughts welcome. We're upgarding to 12.5 in a few months.........