it can be a tough choice for a M->F transgender married to a woman in Australia:

"The Federal Government has refused to issue a post-operative trans woman a female passport [or modified birth certificate] on the basis that she is married to a woman....Abrams, who married her long-term partner Fiona Power using her male birth certificate, will have a legally recognised same-sex marriage if she wins the case."

http://www.ssonet.com.au/display.asp?ArticleID=7029

bkkguy