Guys
I have 2 other threads which relate to this but basically what would happen is I would come in in the morning (not always) only to find certain xslt webparts had failed, when the failure occurred it would always be the same webparts.
I have been banging my head against a wall to get to the bottom of this without any luck as the error is completely random (most mornings it is fine but some mornings the web parts fail).
Anyway I have traced it to the Application pools recycling. I have suspected the app pool recycling for a few days and came in this morning to find the webparts were broken with the standard error "webparts failed, open in SPD blah blah" so I recycled the app pools and bingo it fixed the problem.
So the question is why does the app pool recycling cause this error in the first place? It is as though it not compiling the pages correctly. Note the webparts are based on standard lists but have been edited to add things such as conditional formatting -- they were edited in SPD.
I have examined the log only to find a whole range of errors on the failed webparts from "List does not exist" to "ResolveToken failed to create object type" (could not even find that one on google).
Thanks,
Dan