Question, is there anything wrong with changing jobs prior to the coop board interview?

I recognize that this isn't the greatest thing to do but if an opportunity presents itself in the same field with a significant increase in salary at a reputable company, does this pose an issue?

I should also note that there wouldn't be a gap in employment.

I wouldn't think so as long as you're honest about it but I can't think you're expected to put your life on hold.

If your job actually changes just prior to the interview you should inform the board that your employer has changed and these are your new numbers. Be ready to provide all documentation as it relates to employment as requested by the board in the original package. If the job is going to change but not before the interview it is not necessary to inform the board because it represents a change that will happen in the future (or for some reason: not).

Now what if I've given notice but am still with my current employer? The former principle applies?

I have no problem being honest I just don't want to share more than is needed. Do boards verify employment by calling or does the letter from HR usually suffice?