You may want to install this hotfix which was issued this week for Revit 2013, as it addresses the following issues for Families as well as Revit server.
Part Family:
- Prevents data loss during upgrade of families containing specific material parameters.
- Improves stability and memory usage within graphics display.
- Improves vector print output of transparent elements and masking regions.
- Prevents accidental data loss during cancellation of the in-place family editor.
Revit Server:
- Revit would occasionally report that an operation could not be completed when attempting a work-sharing operation after a period of inactivity, if Riverbed devices were used in conjunction with Revit Server. A subsequent retry of the operation would then succeed. When this hotfix is applied to Revit, this behaviour is eliminated. No changes to Revit Server are required.
http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=21147820&linkID=9273944