I was so sure it would be you replying in no time that I left the site opened just to check your answer. Anyway, I think I'll dowload another OA copy so I can work with no worries and play at the same time. OTOH, I'm sure I read something about the flares thing somewhere, I'll have to dig again in the OA forums for it.
 Installed another copy of OA and gtkradiant would still pick those textures up. The reason is that the autodownload feature puts them in your /home/username/.openarena/baseoa directory, which is read by radiant as well. I just moved those .pk3 to where I have my OA and everything is OK now.
Off topic now, I found this thread in map-center where somebody provided a link to an american architecture school where you can dowload three maps made for the quake engine which are replicas of actual buildings. You'll find there the map Chartres, which I believe was the initial inspiration for dONKEY to make his Amiens map.
Here's the thread of map-center:
And here's the direct link to Knowlton School of Architecture:
See you around and thanks.