Stuttering on neutral throttle

Morning. I have this annoying stutter when the bike is neither decelerating or accelerating off the throttle. She starts fine, idles fine and pulls like a train through all throttle positions but as soon as I achieve any speed and the engine is no longer under strain, the stutter starts. It's almost like a misfire.
The bike is bog standard with regards to intake and exhaust.
On the over run, the bike will pop and bang quite a bit so was wondering if it was over fuelling at all. The thing is, what part of the carb would cause this to happen at all throttle positions? Hard to explain but if I accelerate to say, 30mph with a set throttle position (1/8th), the bike pulls fine up to that speed, then once we get near that speed and the engine is no longer under load, the stutters start. So, this happens at any speed, say 70mph with 3/4 open throttle.
It's not a violent stutter but it is noticeable to the point of annoyance and makes smooth cruising unpleasant.
Any ideas what I should be looking at here?
I'm UK based so altitude shouldn't be a problem. EU XR650R, stock carb, stock exhaust, good fuel and I'll say for now that the jets are standard for EU bike as I have no idea what's in there (currently working).
Looking forward to some ideas chaps.
Gaz.

Nothing like jumping in with a question without saying hello first   ....have you done the basics ?, checked the plug, cleaned the carb out ?

Has the bike been uncorked?
Intake or exhaust leak?
What jets are you running?
Are the jets blocked?
What clip position is the needle?
What is the float height set at?
Is the petcock strainer blocked?
Valves properly adjusted?

Tomo pull the carb out and give it propper good old fashioned clean , easy to do and it usualy works magick , and while you there check what jets and needle you have + the needle position , write it down for future reference .  

When you stop riding the bike and put it on the kick stand or even when trying to kick start the Pig, do you notice any fuel leaking from the overflow tube on the carb?
  

Another one bites the dust , ...   

Told you not to send him those naked pictures Frooty now you have scared him away   

Sorry   

Hehe. Sorry for the delay chaps. On a rig in the North Sea at the minute so things are going slow.
Spoke to a chap on here that reckons she's running lean so I'll be lifting the needle up a notch and seeing if that helps.
Aurora: Nah, no overflow issues

While I'm here, just a quick one which would be a waste of a new thread but where are all the 2007> XR650R's? I'm under the impression they were built up to 2009 is that right? I'd love a minter as a 3rd bike but I've never come across anything on ebay newer than 2004.

Thanks for all the gen though. Can't wait to get home and get the kitchen stinking of 98RON!!!

Nahh stopped building them in about 2004/5....your thinking of L's.....now your getting us worries don't say you have a L model   you will find the odd late registered bike but to be honest they are all the same apart from graphics, very early bikes had a couple of niggles which were sorted by 2001, output shaft seal and clutch bush...

http://www.howmanyleft.co.uk/?utf8=%E2%9C%93&q=xr650r