You were speeding, sorry bud. The limit starts at the sign, not when you see the sign. Happens all the time in small towns. Traffic tickets is their biggest money generator.
Now, I know at least in Ohio, the small towns must LEGALLY apply to lower the limit. For example if Ohio Route 123 goes through Nowheresville and the legal limit on 123 is 55mph but the Mayor of Nowheresville wants you to go slow through town for whatever reason and he tosses up a 25mph sign. It is NOT enforcable unless is is journaized (and it rarely is) so if you get stopped, you can look up the legal limit and if its still 55mph in the journal, you can buzz town at 55. Not that I suggest it BUT if you get stopped for say 35 in a 25, you can get off failrly easily. The town cops don't know this so don't argue with them. They are jsut doing what they are told. Smile, take the ticket then go to court. Not sure if Texas is like this but i know Ohio is.
Oh and 11 over is my ticket. I have got 3 tickets in the last 5 years. All 11 over. 56 in 45 in my Jeep and two 66 in 55 in my truck.

The 56 in a 45 was exactly what happend to you only opposite. I hit the 45mph drop sign at 55,... well I guess 56... then started to slow down. That didn't fly with the cop. 45 AT THE SIGH. Whatever dude, thanks for a break.