I am having the same problem - the foot pedal is unresponsive. I do not have the tap lock engaged. Often, when I release the pedal, the audio continues. Sometimes, when I engage the pedal, the audio does not start. The pedal malfunctions more often than it functions properly. This started after installation of 4.37.
OS - Windows XP Home Edition Service Pack 3 (build 2600)
Install Language: English (United States)
System Locale: English (United States)
RAM - 1.93
PROCESSOR: 1.80 gigahertz AMD Sempron
128 kilobyte primary memory cache
256 kilobyte secondary memory cache
Not hyper-threaded