rattle on start up.

i have a 2001 vectra 2.2 sri. i had both chain kits replaced last november and ive done around 10k since.
when i start the car hot or cold i get a rattle more when cold.
i have been told that its the tensioner and told of someone else that it could be sticking. when the cars warmed up its lovely and quite. the tensioner i got with kit has the rounded top is this the right 1?
anyone has any ideas id be greatfull as its driving me mad!!!!!
can i just take it out without the worry of the timming moving? if its slack it will need replaced wont it? ive had to many people at work telling me differant things its got my head done in. i just want it fixed!
went out today in the car started it and got the rattle for about 8 secs then it went quite rev it to 2500 rpm and its back but go's completly when warm.
been told this could be the cam followers not the chain tensioner? has anyone else had this problem?
at the stage now when iam thinking of putting another chain kit on.
any help or advice would be greatly received thanks.