vw polo 1.2 - starting and running problems....sometimes! - dave750

help,ive got a 54 plate 1.2 vw polo,its in good nick,and had a full service 5 months ago.10 days ago it failed to start first time,this has now happened 5 or 6 times.it starts after 4 or 5 attempts and was running fine.then 3 days ago the engine started loosing power for a few seconds at a time.it only does this for a few minutes after start up.once its been runnuing for 5 minutes it seems fine. the battery is ok,any other ideas pls.cheers