Hi Julie,
You are absolutely correct. Isagent version was responsible for it. We had raised the OSS message and they gave the same solution and answer as yours. I was also in disbelief that why the buggy version is still there or atleast there must be some alert for it. Spent so much time troubleshooting it.
Wish you may have given the solution sooner.
Thanks
Vaibhav Srivastava