Have I stuffed my stepper driver?

Hi guys, I'm using a bigeasy stepper driver from sparkfun, had it working perfectly... Then went to test and work out another stepper I pulled out of a scanner.

Firstly, should I be adjusting the current limiting pot while live? Or should I be turning it off?

Basically I forgot that the silkscreen was backwards and put 1.8A through a stepper that should run at about 200ma, there was a bad smell and I shut it down pretty quickly. Now, the stepper still runs fine at 200ma, and so does the driver but if I turn it up above about 300ma then the driver starts to make a squeeling noise. Have I stuffed it?

there was a bad smell and I shut it down pretty quickly

By the time you smell it, it is too late. Yeah you smoked something. probably the board. You might check it out with a multimeter, sounds like there is some functionality. See if it draws a lot of current when nothing is happening. That would mean you burned a new current path some where. The driver working a low amps and not at higher amps may mean you partially fried something and now you have a high resistance path to output that limits the current and unbalances the steps after a certain load. Either way, the easiest thing is to just get a new board unless you are into removing board components.