Our Delphi 7 development team stores form files (dfm) in text mode, and uses a source control system (Subversion) to track changes.
Sometimes, we noticed that a form file returned to binary format between revisions, causing diff tools like TortoiseMerge to complain.
Using the Subversion change log, I can see that the DFM file was stored in text form before. The software developers never change the storage file format back to binary manually.
Have you encountered the same? Is it a known problem?
I have seen it happen in Delphi 7 when a form inheriting from another form from a different project was opened in Delphi on its own without the project it belongs to being open.