The only possible issue I see with modifying the Federal return to "fix" this, is that your Federal return is part of the CA state return -- at least if you mail in your documents. If my 1040 is submitted electronically as part of my CA state return, which one does CA get? The one that was e-filed and accepted, or the one which was modified but does not match my actual return...?
I'll be on the phone w/ TurboTax support in about 10 minutes, but clearly this is a widespread issue.
