Stalling then starting problem.
 

I recently started getting a problem with my 1999 Coupe 2.0i SE.

I pulled up to a junction and the car stalled, then would not start. I flattened the battery like an idiot trying to start it as I was in a hurry of course! I then called the RAC and when they came and put on the battery pack, it started first time and away I went. It went a week or so, then happened again, but this time I didnt flatten the battery and 10 mins later the car started.

a few days later and this is now happening nearly all the time and it seems that the following is true (been trying to deduce this as I went).

1) The car always starts when cold.
2) Once stalled, it will not start for at least 5 mins, depending on how long its been driven.
3) It will start once its cooled down without fail.
4) It seems to be getting worse - in fact I think it may have reached the stage where its always going to happen, but I may be being premature with that assumption.

The garage I got the car from told me to change the fuel filter (this was after the first incident). Given the following issues, I am not sure that a fuel filter is the answer, but hoped to get some feed back from those more knowledgeable than me.

My guess from a bit of surfing is a temperature sensor, but to be honest I dont know which one - the air intake temperature sensor seems a likely candidate though.

Any help is most appreciated!