I just thought I would suggest this.  If you send 
a regular letter (the 80 cents one) they tend to 
get lost very easily.  I've had this happen to me 
many times, and they can take a while to reach 
the destination.  So, in a case where you have 
already lost a letter once, you should use 
something like a Glodal Priority Letter.  They 
run about $4, but they are much faster (only 
takes a few days) and I have never had one get 
lost yet.