Thanks PepsiCan, I've identified the problem. It will be fixed with the next release.
Speaking of which, just a few days, and a new version will be available...
The current changelog (although I've still some things to add/fix, one which is the highly anticipated property value editor):
New - Ability to delete chunks.
- Import raw chunk added (export was already supported). Be carefull with this though. Incorrect use can make the file you are working unreadable to the game.
- When you run S3D again while another instance is already running, it will bring the existing instance up and terminate the new one.
- Added a file info pane at the bottom. The pane displays the path, dates and size of the opened file. To view it, click the thin blue bar just above the statusbar.
- When selecting an individual property, info of that property is shown: date type, offset, size, etc.
Changed - Seperated resources from main assembly, so it is smaller (for quick patches in the future).
- Renamed propertydefitions.xml to propertydefinitions.xml (doh!)
- Due to some internal changes, all user preferences are reset. I hope this won't need to happen next time...
- Renamed 'Size' to 'Chunk size' and 'Chunk size' to 'Data size'. Sorry for overlooking this. (thanks Anvart)
- Changed behavior of File > Close. Previously, the application would close if the last file was closed. Now, the last window will remain open. Use File > Exit to exit the application. (thanks Anvart)
- Part of the property parser is reworked. These changes generally should improve data type detection. However, because I can't test it on all files all the time, if you find it doesn't open a particular file anymore, please tell me...
Fixes - Fixed a parse bug with cameras.dat (thanks CaptainCox)
- Fixed issue with move up/down chunk.
- Some minor bugfixes
- Color edit control sometimes displayed a descriptive string of the color (for instance: Red) where you expect numeric values. This is corrected. (thanks Anvart)
Improved - Updated installer with logo.
- Updated interface with some visual styles.
Latest screenshot