When you ran the baseline test, did SilkPerformer display any errors whilst executing? if so then that could be the reason why you can't accept the results. Also check the Virtual User log/s, as these can also give you some insight as to why the baseline test failed.
Unfortunately the only other thing i can think of is possibly a corrupted repository.... Have you tried posting on the Segue site as this might be something which needs some serious help. Sorry I'm stumped!?
It seems like there is a bug in silkperformer workload naming
convention. When I have the active workload name as "1 Hour/100 Users
Increasing Workload" and run a baseline test with "Find Baseline", I
can not accept the results. But if I have the workload name
as "Workload1" I can accept the results.