Assemblies/Parts disappearing (SW 2014 SP 3.0)

Hello

We are having a strange issue with some of our parts.  When I open up an assembly (large, >greater than 1000 items typically), And then I go open a subassembly from there, sometimes when I get in to the subassembly, parts are missing from the view.  They remain in the feature tree, but with no "+" next to them.  Supressing and unsupressing fixes it, as does setting lightweight to resolved in the top level assembly. 

However, this is sometimes not feasible because once I open more than one assembly, things slow down dramatically when everything is resolved.  It takes a very long time to resolve thousands of components, and many of them are simple hardware items (rivets, bolts, nuts etc).

Also, when I do have large assembly mode active, it reaches that limit (500 let's say), activates large assembly mode, and then I am unable to resolve components after that.  They refuse to resovle, and I cannot edit a part in context (or even show sketches from that part).

This did not happen in 2013 Sp 3.0.  It's a rather big issue for us right now (well for me it is, once my colleagues start in to some big assemblies soon, they will find it's a problem too). 

Did SW change the limit on resolved components from being assembly specific to globally limiting ?  I have never been restricted from resolving components no matter how many items I had open. 

SolidworksAssemblies