Outdoor Power Equipment and Small Engines - Jonsered chainsaw problem

I recently purchased a new Jonsered chainsaw and am having a problem. I am using this saw to cut my firewood for the winter and am using it in august. after i run the saw for an hour or so and then shut it off, i have a very hard time restarting it. If i do not use the choke, it will not fire. if i use the choke ,it will fire and then quit, if i use the fast idle,it will start and then quit. The primer does not seem to help,as if its not pumping anything.
If i open the gas cap there seems to be pressure in the gas tank as it hisses when opening. Is it possible to be vapor locked ??
After messing around for half hour or so i can finally get it running and it runs great. Any help would be appreciated.
Thanks in advance !!

Hello davecsr!

If it's new, I'd just let the warranty cover it or return it. If you'd rather not, you might wind up voiding the warranty by trying to repair it. If you want to find the problem and repair, post the saws model number so we can find a starting point.

I'm not sure about Jonsered but most top end saws have a baffle of sorts in the air cleaner cover area. One position for warm weather the other for winter conditions. It either opens or closes a port up to allow for cool or hot air to blow into the carburetor area. You will want the port closed in your case, this time of year.