IM65 problem with firmahold gas

I've got the paslode IM65 nailer. I recently got it serviced and since I got it back I have problems firing the firmahold fixings.
Before it went into be serviced I never had a problem with the firmahold stuff but now for some reason I do. I can fit the paslode top onto a firmahold canister and it will fire (granted the gas leaks slightly), it will fire fine with paslode pins and gas too but for some reason the proper firmahold gas stuff doesn't work at all. Any ideas why?
I've serviced the gun myself, checked to see if the firmahold stuff had clogged anything up and everything seems fine

I'm not sure if the problem is the nails or gas.

If it's the nails, are they the same fixings you removed from your gun before getting it serviced?

If not perhaps it is a faulty batch?

If it's the gas, same question? Try another canister or change the canister head if you can?

Sorry for the late reply, the nails work fine it's definitely a problem with the gas because it still works with paslode gas. I have tried about 20 canisters and had it serviced twice and it's still the same. The paslode bloke who serviced it says its the gas that crap but the other lads o. Site have no problems.

Well you've narrowed it down to the gas.

So if Paslode works but another doesn't then try an alternative provider.

I have an IM350 and buy Senco nail packs from eBay, cheap but good.