activesupport classify truncates

Sorry about cross posting, but this is where it really belongs.

I tried to use "my_class".classify and got MyClas as a result. Tried
others that ended in 'ss' and got the same results. Tried other
endings and they work. Ruby 1.9.2-preview3 and
activesupport-3.0.0.beta4 is being used.
Is this correct? If so, why?

Tried it with "my_clas".classify and got "MyCla". It seems to be
dropping the last 's'

Don French