Application handler problems

I have trouble setting up the application handlers so that Nautilus 
would listen.

I installed Open Office (OO, ver 1.0.3) and it has few file extensions 
it handles. (I think it worked OK when I had a previous ver of OO installed)

For some (like .doc and .csv) things work fine in Nautilus.

But for others (like .sxc which is OO native spreadsheet format) 
Nautilus stubornly says it does not have a viewer set up. And in the 
menus for Viewers or Application there is nothing.

In my File Types and Programs dialog these extesnions are properly set 
up to be served by openoffice and their MIME type is correctly set to 
application/vnd.sun.xml.calc

But Nautilus thinks these are application/zip files which is perhaps a 
problem.

As a note: when I run a "file" on these files it indeed reports that 
this is zip type to be handled with v2.0 or better.

But my $HOME/.mime.types lists the .sxc as a vnd.sun.xml.calc, and I 
hope this is what both File Types and Programs dialog and Nautilus use?

I must say this whole MIME and magic business is very confusing. There 
are some many places where there is some database on it ("file" command 
magic database, /etc/mime-magic and mime-magic.dat, /etc/mime.types, 
$HOME/.mime.types). And then Netscape has its own db, I think, and I 
still dont know what Nautilus uses.

So how do I get Nautilus to listen what I put in the File Types and 
Programs dialog?

I am using redhat 7.2 (with Gnome 1.4 I think. How do I check that?)
(I installed RH8.0 with Gnome2 but it was a disaster. I could not get 
the WM to do what I want, I could not switch to sawfish, and many things 
were mysterious and hard to configure. And after a while the whole thing 
crushed, so when I logged in again I did not get any menus or icons. I 
switched to KDE but that is far from perfect. Is RH9.0 any better?)

Thank you,
rafal