Bug: Old versions do not exit, leaves a thread with no purpose

[UnforeseenOcean]

Symptom: When a new version is detected, the old version does not exit. Instead, it spawns a message box saying a new version is available, and if it's closed, leaves a functionless and useless thread in the process list.
Either allowing the old versions to work or exiting the thread when the message is closed will solve the issue.

[Brollyy]

I've known about this bug from Watsu, but forgot to file it in, thanks @UnforeseenOcean!

I can fix this in the new versions going forward, but not sure about going back and hotfixing all of the previous releases...

At least there's a known workaround for this issue: go to the Settings on the newest version and disable "Check for Updates" flag. This will then cause the old version to skip the check as well and launch correctly.