door switch problem

[TONYH]

got my 4.2 3 weeks ago and have done 900 miles - used it everyday so far. Parked it last night with windows open and alarm not on - this evening, drivers door wouldn't open from the outside. Put alarm on and off a few times, turned immobiliser on and off - no difference - done a search but nothing definitive as to how to fix it - any ideas or is the switch on the outside knackered - any advice would be appreciated.

[TONYH]

thanks for the advice Bob, problem gone today but I think it may come back. Who/where are RS? I have seen the name come up a few times.