Here's a problem on a W-2 I've received:
The Social Security withheld ($856) does not equal 6.2% of the taxable Social Security wages ($14441) (Form W-2, boxes 3 and 4). It is $39 short.
The Medicare withheld does not equal 1.45% of the taxable Social Security wages (Form W-2, boxes 5 and 6) It is $9 short.

I assume that the IRS wants SS withholding (and employer tax paid) to be rather exact, since I'm not aware of a way employees can adjust their SS paid on their 1040.

Should I insist that the employer correct the withholding error and issue a corrected W-2 before I file? The employer's accountant initially said just file with what I have. Will that invite an IRS review and delay the refund? Or am I blowing this out of proportion?