My MS Connect membership doesn't cover Exchange so I can't go there to validate this; however I can verify that I see exactly the same issue using my WM6.1 and Exchange 2007 via 4Smartphone.net
I don't use a lot of tasks, so had not seen this before, but ironically in the course of preparing the review of SBSH Calendar Touch this week I did need to test the Task functions, and came across this issue
