There is an updated version of Revit DB Link 2011 available on Subscription Center at the link below [login required]: Subscription Center - Revit DB Link 2011-02-10
This release includes a number of performance, memory utilization and stability improvements.
With this updated version it is important to keep in mind the log files are now stored at the following location:
Vista \ Windows 7 - C:\ProgramData\Autodesk\Revit DB Link 2011\log
Windows XP - C:\Documents and Settings\All Users\Application Data\Autodesk\Revit DB Link 2011\log