Whatever the problem, it's not all instances of two Tulip boards; I've 
been running this way for about a year on 1.6.x:

$ dmesg|egrep tlp
tlp0 at pci0 dev 9 function 0: ADMtek AN985 Ethernet, pass 1.1
tlp0: interrupting at irq 10
tlp0: Ethernet address 00:0c:41:22:cc:01
ukphy0 at tlp0 phy 1: Generic IEEE 802.3u media interface
tlp1 at pci0 dev 11 function 0: ADMtek AN985 Ethernet, pass 1.1
tlp1: interrupting at irq 12
tlp1: Ethernet address 00:20:78:1e:1f:ef
acphy0 at tlp1 phy 1: ACXXX 10/100 media interface, rev. 0


		--Steve Bellovin, http://www.research.att.com/~smb