just called tsa at iah airport...they gave me a number to call for the "SOCC" office(281-443-5341)i was told that if the picture and name match no problem....the man i spoke with said his name on his passport is "thomas" and on his ticket it might say "tom"....i'm at ease after this call...if you have doubt, give them a call...u can get the number for any tsa or socc office, by going to the airport which u are departing from...
happy travels!!!