A tax-preparation glitch could delay the returns of an estimated 30 thousand Ohioans by up to six weeks. The Internal Revenue Service says the glitch will affect 660 thousand tax returns nationwide. A problem with a limited number of software company products affected some taxpayers filing a form used to claim educational credits between February 14th and 22nd. Kansas City-based H&R Block has been informing customers about problems. Spokesperson Gene King says the problem also involves other tax preparers. He insists the returns were prepared accurately, but the error occurred in e-file processing.