Since the IRS is no longer taking calls due to personnel shortages, nothing can be resolved with them over the phone. It wouldn't help you anyway since they cannot reveal who might have claimed you. Since an accepted return shows you as a dependent, you are not eligible for the stimulus payment this year.
You can, however, go ahead and file a return claiming yourself, by paper and through the mail. The IRS takes a long time to process paper returns but eventually you will receive a letter from them asking for more information.
If this is straightened out by next year, you could receive the stimulus when you file your 2010 tax return next year.
