Outlook 2010/13 Laptop Calendar access extremely slow after opening shared calendar

Question

I have a problem with several laptops running Win 7 Ultimate on a network running SBS 2008 (Exch 2007) when they are on the internal network. Outlook response is fine until they tick any shared calendar (either shared by the user or with full access
to the mailbox granted at the server level)- the response of the calendar screen for the
local users calendar  or the shared calendar
when using the advance or retreat arrows on the weeks drops down to roughly 20 seconds to advance to the next week, if the shared calendar is then unticked the speed stays slow for accessing the local calendar. if the user exits outlook and restarts
it the speed for accessing their own calendar returns to normal until they open another shared calendar.
this is a problem that has started within the last couple of months. SP are up to date on the windows and office.
I have tried ticking the download shared folders on and off, and also switching to using HTTP instead of TCPIP through the outlook anywhere. they run in cached mode as they are laptops- uncached is not an option
network access is fine
The problem affects some users on the network but not others. the problem shows on office 2010 and 2013. they don't appear to have the problem when they are out of the office.
Any thoughts anyone?

Answer 1

If you run your profile in Exchange cache mode and enable "Download share folders", please try to run SCANPST file to fix the OST/PST file and check the result.
http://support.microsoft.com/kb/287497/en-us
By the way, does it for all shared calendr when you go to access them?
Tony Chen
TechNet Community Support