I encountered the same issue when upgrading to 2008.11. Even after recompiling myk, still no luck.
Fortunately the Marvell yukonx driver (available from their website) now seems to be compatible with OpenSolaris, at least version 10.0.3.3. The previous version 8.19.2.3 was not compatible with 2008.05. -- This message posted from opensolaris.org
