Hi,

After some research my next step is to try

DBCC FREESYSTEMCACHE (‘TokenAndPermUserStore’)

And see if that has the same effect as DBCC FREEPROCCACHE

Right now the tokenandpermstore cache is 791mb/1874000 entries and running ok.

I will see what it is when it next runs slower.

There is a well documented issue with TokenAndPermUserStore which I have so far overlooked as we are on sp2 however some posts suggests it could still be the cause.

Thanks

Simon