I am sorry I wasn't more specific when I made the suggestion to drill a hole in the handle. You said you "drilled a hole in the END of the rod handle" (emphysis mine). If you drilled a hole in the end of the handle, you probably did not get to the empty space that is causing the vacumn. I would try to drill a hole one more time.

Try drilling in the side of the handle just an inch or less back from the part that holds the reel seat and trigger. I am not familiar with your flippin stick but I have a BPS Extreme. I just measured where I made the hole in my stick. It was 13 inches from the receptical end of the handle (the opposite end from the butt) and about a half inch from the reelseat section. When you are drilling, you should feel a "soft spot" when you hit the empty space inside the handle.

I hope this works--if not I don't have any other suggestions.

Grumpy