Revit link that disappears

(I've found lots of posts about 2D cad links that disappear, this post is about Revit links that disappear.)

One of our Revit drafters is working in a project with a number of linked Revit projects of surrounding buildings. Each linked project is in its own workset. When she opens the project one of the buildings, always the same one is not shown. We have checked and

* the workset holding the link is open (Collaborate > Worksets)
* the link itself is loaded (Manage > Manage Links)

When she reloads the link it becomes visible again for about 10 minutes. She reports that it does not disappear in connection with Synronize with Central.

Any ideas what's going on?

What's the combined file size? (active model + all linked models)
Computer Specs?
Just wondering if you're running into memory issues or something like that.

I guess it's this calculation I need to do: http://bim9.com/2012/01/13/how-much-ram-do-i-need/ ?

I also just found this hotfix: "Hotfix – Autodesk Revit 2012 – Error with linked model visibility with custom settings": http://usa.autodesk.com/adsk/servlet...linkID=9273944

Hey, do you get an email telling you I've just posted? I didn't get one for your post and I can't find the settings for notifications...