ruby: no such file to load -- ubygems (LoadError)

[coachhilton]

Greetings,

After having used Ruby for some time, first on Windows and Linux, my
colleague and I together decided to upgrade our WinXP systems to Ruby
1.8.4. He used the Window's installer version while I decided to build
my own. Coincidentally, we're both getting the same error when trying
to test our installation w/a simple helloworld.rb applet.

ruby
p "test"

upon hitting enter and BEFORE I end the file for ruby to process the
stdin, we get the following error:

ruby: no such file to load -- ubygems (LoadError)

irb runs just fine, btw. Any idea what's wrong here?

Thx,

Ken