I've read a few articles as to why performing an IISReset is not safe as it doesn't completely save XYZ (can't remember exactly what now).
What is the safest alternative to IISReset?
I ask this because I did an IISReset on one of our servers on the weekend and the exchange store service froze in the 'stopping' state - ended up fixing it by killing the store.exe process and restarting the service.
As far as I know, iisreset doesn't stop the Exchange Information Store - only the SMTP service.
You could try iisreset /noforce or you could fire up IIS Manager on the server and from the menu choose Restart Internet Services on [server name] (which for all I know, could just be doing iisreset /noforce in the background).
I have to bounce IIS on our Exchange server periodically (3rd party app keeps crashing) and personally, I use the GUI as I seem to have more luck with it.