FindMinimum never returns

[mcmillab]

Hi,
I've been using this library for a couple of weeks now, thanks very much.
On occasion, FindMinimum never returns a value. Presumably it is stuck in a loop (one core is being using from looking at Task Manager), however the objective function is not being called.
Is that something you've experienced?
Is there a fix, or way of setting a timeout?
thanks
Ben