Last year we got the opportunity to do a river cruise, but they only gave us about 3 weeks notice. We checked our passports and found they expired less than 6 months after our return, so we had to get them renewed in a hurry. We paid for expedited service and sent them out on Thursday - got them back the next Friday - thought that was awesome.
The only thing was when we went to mail them at the post office, the clerk said we had to put them in separate envelopes. I told her that was not the case. She had to call the postmaster who confirmed we only had to use one envelope to send them. As Moiraine alluded to, often times when you're dealing with the government (or a government agency), the right hand has no idea what the left hand is doing.