TrueMobile 2300 wireless router problem.

This maybe an easy question I don't know, but I got a problem with fast blink lights on this TrueMobile 2300 wireless router.   The wireless part is working fine, the hard wired equipment is aving a problem. 

Our setup:

1 Wireless laptop

2 pcs already conntect via cat5

We have at least 3 more to connect.  There are only 4 ports on the hub.  We connected a 4th pc via a hub just to see if it would work.  It took right off fine, no problems.  Now when we try too hook up any computer straight to the router that is not already hooked up it, the indicator lights flashes green very fast.  The computer says that it is connected(sometimes), but I am unable to see any computers in the workgroup from the newly connected pc.

Anyone have any ideas.  I've looked at all the FAQs I can find and I can't find what that fast flashing green light means.  Any help would be appreciated.

Thanks

Chris