SS and Medicare refund
Well, many companies would not like to have differences in the day to day accounting. So by default, they would cut the SS and Medicare taxes. You can always ask for a refund from the company. If the company denies to refund, then you can fill couple of forms (dont know top of my head, but can let you know if you still need the form#) and mention that you contacted the company who denied. This is how my previous company used to pay the refund. For another company who didnt want to pay, i filled the forms and got refund aswell.
Hope this info helps.
eagle2004