Add a user dictionary and close the option dialog. Then open again. The original dictionaries are not available anymore.
Also fixed the problem with default locale not being used to already opened files (until closed and reopen):
Integrated into 'main-golden', will be available in build *201006120001* on http://bits.netbeans.org/dev/nightly/ (upload may still be in progress)
User: Jan Lahoda <email@example.com>
Log: #187425: using InstalledFileLocator.locateAll to find dictionaries instead of trying to find them in netbeans.home and netbeans.user.
Please verify bugfix for this bug, so it can be included in release691 repository.
Transplanted to release691 #96ea89c090de
Verified in NetBeans IDE 6.9.1 Dev (Build 201007062301).