immobiliser (sp) help!!

[fUbAr]

i got in my car earlier today and the bloody thing wouldnt start... it was turning over but the immobiliser (sp) light was flashing really quickly. I took key out, put it back in and it did it again!!? third time was lucky and the thing started like normal.... any ideas folk?

Ta.

 

[JAY172]

faulty key head or reciever ring around ing barrel.

 

[fUbAr]

... ing barrel? ( i knew i could rely on u jay)