I have the same issue with my Infinty foot pedal.
I know it's not a software issue, because I've tried using the pedal with several different software programs, and I get the same problem.
I just switched the button designations for Play, Rewind, Fastforward, as suggested in this thread. I tested the results for a few minutes, releasing and pressing the Play pedal - works perfectly so far.
I'll be transcribing a lot tomorrow - I'll try to update re. results.
EDIT: This worked like a charm!
Many thanks to the people who posted this