uninitialized constant ImageList

I keep getting this error:

NameError : uninitialized constant ImageList

from this code:

helloworld = Magick::ImageList.new("helloworld.jpg")

I really want to get this to work, ive tested for days now, EVERYTHING
except this feature interacting with my application is working.

Ruby : 1.8.4
Rails: 1.1.6
ImageMagick: 6.2.9 Q8
RMagick: 1.13.0

OS: Win32

Manually writing the code in an IRB session works 100% perfectly.
Performing the ImageMagick Tests work perfectly, running the example
scripts from RMagick run perfectly, as soon as I move this line into my
application I get that annoying error.

Im really trying to get going with the whole ruby on rails thing.. but
this is too hard for me to figure out on my own right now.. so please
someone explain what the heck is going wrong and how to fix it

-thanks!