Incorrect W-2 - how long to wait for corrected

I found incorrect information on my PA 2001 w-2 (over reporting fed and underpaid local taxes). I called my former employer (a large public accounting firm) to report the problem. They agree that my w-2 is incorrect and they need to send me a corrected w-2. However they do not know how long it will take to send the corrected form. It's been over a month now and they still don't know when they can get the corrected form out. My question is if there is a timeframe that they legally have to get the corrected W-2 to me? and if there isn't, do I submit my taxes with incorrect information to meet the deadline?

TIA

I suggest you wait for the corrected W2, but if it does not come before the time for filing, submit your 1040 with the correct amounts, but explain in a note that the amounts disagree with the W2, that the W2 is incorrect, and the employer is sending you a corrected one. Then when the corrected one comes, submit it.