Do you think these would still be causing problems, even after uninstalling?
Not sure, I use several C::B installations for testing purposes under my home-directory and it works.
Nevertheless, you can try what happens if you remove the empty (or no longer used) C::B directories in the systems standard paths, like
/usr/lib[32|64]/codeblocks,
/usr/share/codeblocks, and make sure that no libs or binaries of C::B remain in
/usr/bin or
/usr/lib[32|64].
You can also start C::B and copy and paste the content of the "Code::Blocks"-tab in the "Logs & others"-pane.
We should see where it searches for lexers and plugins there.