If you can’t get access to the code where the timer is set Nick’s answer may not work, so all that I can think of is this hack.
It is a hack, use with caution!
// Set a fake timeout to get the highest timeout id
var highestTimeoutId = setTimeout(";");
for (var i = 0 ; i < highestTimeoutId ; i++) {
clearTimeout(i);
}
Basically it grabs the highest timer id and clears everything less than that. But it’s also possible to clear other timers that you do not want to clear!