rsterling,
The problem *may* be that you have more than 2 <10-week periods for general areas in your search, or more than the total choices allowed by the online entry - that has happened to me more times than I can count, usually by errors by VG's (they have continued some search I no longer wanted) - and usually they have no idea why you are having a problem.
Now that I know the usual culprit for this problem, sometimes I can persuade a VG to check to see all the searches going, and clear something out. But sometimes they say they have, and it hasn't gone away, and I still can't modify my search. I'll call back and sure enough, more than the allowed # of online searches are still going. Occasionally in desperation I have to cancel the search (lose my place) and start again. But this has always been the reason. It took me months to figure this out.