There is no USB support in the 900c kernel yet. Actually there isnt alot working in the 900c kernel yet as this project is very very young yet. So you may be waiting for awhile until everything is sorted out and pushed so it can go into the next vanilla kernel. Right now everything is patches for 2.6.17.11, which you can find on the linux 900c thread for now.
Also cosmo0 has joined jlime as the 900c kernel maintainer, so more than likely any new updates/news will be posted over on jlimes forums.
(
http://www.jlime.com )
Cheers.