Hi Vizzle,
I really recommend that you upgrade all existing SAV clients from 10.1 MR4 to the latest available release, MR9. MR4 has known vulnerabilities and was not designed to process definitions files as large as the ones currently in use. Stability and security are much better in MR9.
Keep in mind that upgrading SAV does not automatically upgrade the Reporting Server or Reporting Agents... there are many reporting fixes in MR9 that were not in place in your current version. I do not know if the directly correpond to what you are seeing, but it's highly likely that moving to MR9 will resolve the trouble.
Please do keep the forum up-to-date with your progress!
Thanks and best regards,
Mick