"At this point we've got the application pool recycling often to try to prevent this."

I would term recycling the application pool as a "fix" since that would mean throwing out the currently logged in users and making them re-login...right?  The error seems to be pointing somewhere, but the only point is how can this be reproducible. Particularly, all the reportings of this happening is on the production servers...thats even sad!!  I am hoping that the guys who wrote this code are also aware of this thread!

regards
Harish

just wanted to say that we receive the same error... 4.6.0. index out of range, directory`2 etc... it only happens on ONE of our live applications, and we have hundreds, resaving the web.config 'solves' it... until it happens again

My website has just had this issue.  I am a little bit of a newbie, so if someone could please explain in plain English what I need to do, I would appreciate it!  i.e.  in what file would I find the cache loading logic for tabs? 
I also read that you could "touch" the web config file.  Could you explain what exactly I need to do there, so I can fix the problem right away?  After this I will do the "fix."  Or can I just do one?   I can't access the host page, so I can't restart the application, unless someone knows where else I can locate it.  The only page showing up on my site is the Home page. 

Thanks!
Michelle