I was re-reading some of B Mayfield's collected posts/conversations and the wiki and I rediscovered a technique that I found helpful. After inserting the Aneros, gently lift the p-tab, push it closer to the anus, and then gently push it into the perineum. The success of this probably varies between individuals (it may be that my "sweet spot" is closer to the anus than I thought) but it worked for me. Try it out. It's always worth reading over (or re-reading) the helpful suggestions of the more experienced members.
Thanks for the info I will try tonight!