From the mailing list:
I've just downloaded OpenSCAD, (OpenSCAD 2012.02.28)
and run it under Ubuntu 10.0.4
I opened several of the supplied example files (Great idea to provide them!!), and then started to modify one as a learning exercise.
I did "Save As" with a new name, then "Save" repeatedly, as I worked on the file, and after many iterations had a close copy of a model I'd used elsewhere.
I then opened another example file, then attempted to reopen the file I had done all the work in.
I was a bit surprised to find that it was NOT in the "Recent" list, nor could I find it from the "Open" menu option.
I then searched for the file via a file manager, but could not find it anywhere. I closed and reopened OpenSCAD, but the file still did not appear in the "Recent" list.
I then replicated the problem by trying to save to a couple of directories where I did not have permission to write a file, and in each case there was no feedback that the file was not written!
This seems like a bug to me.
I was able to "Save" successfully to directories where I did have write permission, and in these cases the filename appeared in the "Recent" list, as I expected.