That's a definite possibility. One of the reasons I use PGA - it evaporates really quickly. Another possibility (unless you already did this) is to recheck the bottom nut (in the top cap) after putting your DID on a PV. Sometimes the pressure on the pos post is enough to lift it and loosen the connection and then when you take it off it settles back down and you can't tell. Other possibilities are micro-shorts (wick touching bottom or top or inside wick hole) all fixed by pulling wick and re-oxidizing.
