NAV 5 and Vista cache problems  

Incompatibility  that exist between Windows Vista and NAV client, for example  the mangement of cache memory doesn't function very well, because some times we lost any object correctly modified and stored!

--> That actually has nothing to do with Vista compatibility.

It's caused by object cache, and it has always been like that. It is why you have to restart the client, just to make sure an older version of the object is not stuck in cache. If you set the object cache to 0 on all clients, no object will be stored in cache and it will always get the latest version. Of course it might not perform as fast for the same reason.

https://community.dynamics.com/forums/p/13157/18322.aspx#18322