This issue, as well as network load times (UNC path names different between mac and PC), hotlink load times, library load times (file looking in vain in all the wrong locations for these links), and switching workspace on the fly, tweaking layer combos, etc.... is one of many that forced us some months ago to abandon teamwork.
We will try again with v10. For the moment, we separate workspace by hotlinked files only.
Viewsets reside in the 'Mother' file, the sum of all hotlinks. I believe there is a cache somewhere on 'Adrian's' machine, that tells viewsets how to behave, if someone else goes in from a different machine as that same user, u r doomed. I am sure there is a more precise and detailed explanation someone is sure to step in and offer, and while I stand to be corrected, I must say I cannot let this happen again.....hence our abandonment of teamwork like a malformed infant in the snow, cruel but necessary!