Currently Camtasia Studio ships with 6.1 of Xceed.dll which is referenced in the article below.
Our development team is currently looking into this issue. We have had reports of users manually copying version 6.5 of the xceed.dll file into the folder below
C:\Program Files\TechSmith\Camtasia Studio 7\
TechSmith has not tested manually updating the dll file and cannot be sure that no side effects will occur.