I have observed the same problem with lii(4) not linking up running the latest i386 snapshot, and using a 10 meter patch cable to the switch. However, when trying a short 1 m cable to the same switch port the link comes up! A fresh kernel build this past weekend from CVS exhibits the same behaviour.
Interestingly, under Linux/Xandros even the 10 m cable works fine. Eventually, some MII parameters in lii(4) need to be tweaked to make link detection work also for longer cables? I am not afraid to try and compile a patched driver on a fresh CVS tree, if there are any suggestions which parameters to tweak. Rolf