Problem with Insert Send Assistant

I wonder if anyone else has had a problem with the insert send assistant in X2? I am running in WIn 7 with 16Gb memory, Sonar installed on samsung SSD drive and a Roland UA101 USB interface. X2a has been totally rock solid with zero crashes, no issues at all... until yesterday. I got the sonar ended unexpectedly error when I tried to use the insert send assistant to insert a send with channel tools in the fx bin. I could repeat the crash . I got the same error when I tried to insert with an fx chain in the bin. In both cases Windows was still running but I could not restart Sonar without a reboot. (which takes about 20 seconds thanks to the SSD drives!)I could insert the send fine as long as I did not use the assistant to load the FX in the FX bin. And I could insert the fx in the bin afterwards
I must confess I never used the insert send assistant in the past on X1  (only learned about it due to the Groove3 videos. Is there some trick to this - like don't try this with non- 64 bit plugs in the project or with UAD plugs in the project? Or is this a problem I should report?