Hi Noel- did as you suggested. Pristine copy of PT installed with all the defaults it asks for. Created a new piano tracks and played around with it for a while. No problems.
Next, reinstalled drivers for ASIO.
Loaded previously created .seq file, activated ASIO, and started to work with it in new PT install. Shutdown after about 5 minutes.
Sent the error log to support. At my wits end now...
Bernie