Sounds right to me. Mine would surge too. Resoldering my board does indeed fix the problem, as my car cruises sweetly now. It is possible to get the board out without taking the metal enclosure it resides in out, which is much more difficult. You have to pry the enclosure tabs back once you have the enclosure out of the car anyway. I didn't find the need to take the enclosure out of the car at all.

I have posted my experience resoldering that board on the forum before. If you can't find it, email me at jtsdirect @ hotmail.com and I'll walk you through it.