Mapscript srs resetting

[Marcos Sánchez Provencio]

I have to serve data stored in utm30 and utm28 (Continental Spain and
the Canary Islands) reprojected to utm30 (Continental Spain except
Galicia), utm29(Galicia) and utm28(Canary Islands).

I am creating the map from scratch in Python mapscript. The client is
mapbuilder wms. I am setting the map projection for each query with
setProjection. If I start the server and immediatly ask for utm29 it
works fine. Then I ask for utm30 and it works fine too. I ask again for
utm29 and it shows utm30 (some shapes not shown). But if I then ask for
the utm28 map, it shows fine :-S

The server is the django test server (to rule out threading/process
problems).

Any suggestions?