Problem running file from pushbutton which doesnt occur when evaluating command in GUI code

Hi,

I'm currently very confused about this.

In my callback for a pushbutton it runs an .m file which contains a while loop in it.

If I highlight and then evaluate it, there's no problems, it runs the file and the loop goes round as it should.

However, when I run the whole GUI and press the button it only goes through the loop once.

It doesnt matter how many times i do either, or what order i do it, evalutaing the bit in the callback works but the pushbutton doesnt.

Why is this?

Thanks,

Henry