Happened to me twice. I had my VBC buggy set to stock spec and went to a race just to find out that they only ran mod. Well I swap motors in less than 10 minutes but was SOL when it came down to program the SP ESC as I had stock0 firmware in the card and couldn't add any boost of timing or reverse. That is the only down I had with SP. Other than that it was a very good esc. I burned by plugging the negative bullet connector into the positive side of the battery by mistake. OOOPS! LOL.