Ok, here is what I had to do to get my SunPCI II card working with Solaris 10 at work:
1. Install SUNWspci2 v2.3.2
2. Install patch 113616-06
3. In /opt/SUNWspci2/drivers/solaris link sunpcidrv.2100 -> sunpcidrv.290
4. link sunpcidrv2100.64 -> sunpcidrv.290.64
5. Run sunpcload to load the kernel modules
6. Boot up the sunpci card as you normally would, life is good again.

SunPCI2 should now work - with one exception that I found
I ran across a problem that the passthru ethernet driver would cause my sun to panic on a bad trap. To fix this, I booted Windows 2k in single user mode, and disabled the sun NDIS device in device manager. The SIS network interface on the sunpci card does still function.