Relative_path_from error

Hello,
i tried to run the command

ruby script/generate scaffold Item Manage
, but i got the following error:

ruby script/generate scaffold Item Manage
D:/eclipseSE/eclipse/plugins/org.jruby_1.1.6.8388p3/lib/ruby/1.8/pathname.rb:712:in
relative_path_from': different prefix: "C:/" and "C:\\Documents and Settings/admin/workspace/store" (ArgumentError) from D:/eclipseSE/eclipse/plugins/org.jruby_1.1.6.8388p3/lib/ruby/gems/1.8/gems/rails-2.2.2/lib/rails_generator/lookup.rb:110:inuse_component_sources!’
from
D:/eclipseSE/eclipse/plugins/org.jruby_1.1.6.8388p3/lib/ruby/gems/1.8/gems/rails-2.2.2/lib/rails_generator/lookup.rb:109:in
`each’

I really don’t know what’s wrong, or what should i do to solve thie
problem. Please help me…
I’m using Aptana Radrails plugin in Eclipse 3.4.1
Thanks