Hello,
Been a long time since i’ve done this, but have had a few ideas lately.
I’m currently using Windows 7 RC and have setup GtkRadiant 1.4. The thing is, as some people have found out, the save functions don’t work on Win 7 or Vista. Problem is i hate version 1.5 more than i do Vista!
The autosave function does work however, which puzzles me as to why a manual save will not work.
I’ve been playing around and have discovered the following:
If you start a new map and start building, you cannot save, save as or save selected.
If however, you open a map (this can be just a single brush) you can then save as normal.
You still can’t save as, but all you need to do is goto the maps folder and rename the file.
If you try a save as or save selected, then the save function will no longer work. You will have to re-open the map.
The only thing i can’t do, is save selected. For this i have to use 1.5, save as .map and import it in 1.4
So, if like me you use Win 7 or Vista and don’t like 1.5, all is not totally lost.
I’m not a programmer, but it seems to me that its not completely broken. I was wondering if someone with the skills (knowing the above) might be able to fix it. (That is if no-one has done already, although i havn’t found anything).
Many thanks 
P.s. I’ve heard of a 1.6 version based on 1.4 is in development. Havn’t found much info on it but perhaps this new one will fix the issues.