compass_twitter_bootstrap different path

hi everybody,
i'm working on an app based on rails 3.2.6.
for a particular reason i have to install all the gems in a local folder
inside the app (vendor/gems/folder_name)
i've install compass_twitter_bootstrap successfully but when i try to
import the stylesheet (@import 'compass_twitter_bootstrap') i receive
this error:
File to import not found or unreadable: compass_twitter_bootstrap.
it seems a path issue. i've tried to add the folder into the
config.assets.paths but nothing seems to work.
any tips?

Can you post something more on the stacktrace of the error?
Or, is it that the manifest, where definitions of CSS and JS lives
(under /app/assets/... ) is not finding the files?
Alternatively, you could report the issue at Github under the Gem's issues