Dave, it is most likely the cache dat file with Dreamweaver that occurs after installing extensions. For some reason, it gets corrupt and makes everything haywire. You should get in the practice of deleting it every time you install a new extension. It will help alleviate most problems.
For Windows users
1. Close Dreamweaver.
2. Open a Windows Explorer window.
3. In the Address bar enter %appdata% and click Enter.
4. Open the Adobe directory.
5. Open the Dreamweaver folder for the version of Dreamweaver you are using.
6. Dreamweaver CS4 users only – open the en_US directory.
7. Open the Configuration directory.
8. Locate the WinFileCache.dat file. There may be some other numbers appended to this filename.
9. Press Delete to delete this file.
10. Open Dreamweaver.
Note: If the problem persists, you may need to uninstall your extensions, reinstall them, then delete the WinFileCache.dat file and open Dreamweaver.
For Mac OS X users
1. Close Dreamweaver.
2. Open your OS X Finder.
3. Navigate to the following directory.
Dreamweaver CS4
/users/[username]/Library/Application Support/Adobe/Dreamweaver CS4/en_US/Configuration/
Dreamweaver CS3
/users/[username]/Library/Application Support/Adobe/Dreamweaver 9 /Configuration/
4. Locate the MacFileCache.dat file.
There may be some other numbers appended to this filename.
5. Press Delete to delete this file.
6. Open Dreamweaver.
Note: If the problem persists, you may need to uninstall your extensions, reinstall them, then delete the MacFileCache.dat file and open Dreamweaver.