I've been unable to find the exact story and text of the law but I have found this quote that might be about it.
Majority Republicans in the Legislature this year changed election law to prevent candidates from running for federal and state offices in the same election, mostly out of concern that Strickland, the Democratic nominee for governor, would also try to keep his seat in Congress. Democrats argue that the rule prevents Padgett from running for different offices in separate primaries within the same election cycle. But experts say the law would not apply because the primary and general elections should be considered separate elections.
-- Akron Beacon Journal
If this really is the story behind the law then it appears the Republicans might get what they deserve.