I've never had this particular problem, but I do second the opinion that you should do what feels good to you and not do what doesn't.
The only times I've NOT had an orgasm from oral sex, something distracting was going on, like the TV was on, or there was distracting music on or something. That and technique. The first girl who ever gave me a blow job was not particularly skilled. Fortunately, lurkette much more than made up for those early experiences.
