[Berlios seems to be down (except for the svn subdomain) so I'm posting it here]
If I double-click a .cbp file in Nautilus, I get the following message:
Cannot open os.cbp
The filename "os.cbp" indicates that this file is of type "Code::Blocks Project". The contents of the file indicate that the file is of type "XML document". If you open this file, the file might present a security risk to your system.
Do not open the file unless you created the file yourself, or received the file from a trusted source. To open the file, rename the file to the correct extension for "XML document", then open the file normally. Alternatively, use the Open With menu to choose a specific application for the file.
So basically it's refusing to let Code::Blocks open a .cbp file because it's
also an XML file.

Fortunately, the fix is pretty simple. Apply this patch to
trunk/src/setup/mime/codeblocks.xml:
--- codeblocks.xml.old 2006-12-29 20:24:53.000000000 +0100
+++ /usr/share/mime/packages/codeblocks.xml 2006-12-29 20:23:43.000000000 +0100
@@ -3,9 +3,11 @@
<mime-type type="application/x-codeblocks">
<comment>Code::Blocks Project</comment>
<glob pattern="*.cbp"/>
+ <sub-class-of type="application/xml"/>
</mime-type>
<mime-type type="application/x-codeblocks-workspace">
<comment>Code::Blocks Workspace</comment>
<glob pattern="*.workspace"/>
+ <sub-class-of type="application/xml"/>
</mime-type>
</mime-info>
(And then
sudo update-mime-database /usr/share/mime && killall nautilus
to make sure it's using the new data, if you want to use it right away)
I'm using "svn build rev 3357 (2006-12-07 14:24:20) gcc 4.1.2 Linux/unicode" (Specifically, the Ubuntu Edgy build posted in
this thread, IIRC)
I know this is a bit old, but it looks like the relevant file in SVN hasn't been touched since February, so I'm pretty sure this hasn't been fixed yet...