It so happened that without doing anything (or so I thought!), my AceStream stopped working. Each time I tried to start it, I got this message:
ace_engine.exe has stopped working
Looking through the registry, I found a connection between AceStream's engine and Quicktime, which I had recently updated to the latest version. Ha!, so Quicktime was the culprit.
I uninstalled Quicktime, uninstalled AceStream and reinstalled AceStream after rebooting. It works fine now and I can go watch some Premier League games