Hi Lynne, thanks for the reply. It doesn't happen all the time with him, maybe once every 4 - 5 days and it is only with this same user. I haven't done any changes or added any mods for quite a while. I've been looking for 'threadread.readtime' errors as that seems to be the common denominator, but can't find anything. I'll keep looking.
Thanks again.
--------------- Added [DATE]1345015947[/DATE] at [TIME]1345015947[/TIME] ---------------
Just found this and will look into it on my next day off
https://www.vbulletin.com/forum/arch.../t-160713.html