Whenever I require a file in ruby or irb I get this error:

LoadError: no such file to load -- (insert any filename).rb
    from <internal:lib/rubygems/custom_require>:29:in `require'
    from <internal:lib/rubygems/custom_require>:29:in `require'
    from (irb):1
    from /usr/bin/irb1.9.1:12:in `<main>'

It happens even if the file exists I am using ruby1.9.1 and to my knowledge, I have not installed rubygems. I am running on Ubuntu 10.10 Maverick Meerkat. Please help, this problem is very annoying! Thanks in advance, ell.

EDIT: I forgot to say that no matter where the file is, even if its in the same directory and definately exists I always get this error.