I've been using OpenVPN on DD-WRT for a while now and there has been one thing that has been bugging me for some time. It has to do with the fact that defining the IP range for the OpenVPN clients doesn't ever seem to work.
I've already posted a ticket to the dev of dd-wrt and he said it's an issue with OpenVPN and I need to bring it to the OpenVPN folk's attention.
This link has the full details of what I'm doing and what's happening.
Also have a little trouble getting the gateway-redirect to work correclty when using TAP (vs TUN) but one thing at a time.

Here's the version of OpenVPN that is on the latest build of dd-wrt:
OpenVPN 2.1_rc15 mipsel-unknown-linux-gnu [SSL] [LZO1] [EPOLL] built on May 8 2009
Thanks in advanced