Please clarify what form you are posting, and where do you see the adjustment occurring?
I posted the Bond Premium from box 11 of my 1099 and the TT adjustment is a deduct from interedt income on schedule B
The first step would be to review your 1099-DIV entries to make sure the correct number was entered and that you don't have duplicated entries.
If you still have a difference, it may have come from a K-1.