i suspect that you have both ukphy and nsphy PHYs in your kernel and
your hme's got hooked to the ukphy PHY.  try building a kernel without
ukphy.

at least, this was the symptom and hack for me with 1.5ZC.  but, the same
config under 1.6D results in unconfigured PHYs.  at least it still passes
pkts.

so, i end up with

oak [4] ifconfig -m hme0
hme0: flags=8a63<UP,BROADCAST,NOTRAILERS,RUNNING,ALLMULTI,SIMPLEX,MULTICAST> mtu 1500
        address: 08:00:20:d9:1c:68
        media: Ethernet manual (none)
        supported Ethernet media:
                media manual

hme0 at pci1 dev 1 function 1: Sun Happy Meal Ethernet, rev. 1
hme0: interrupting at ivec 3021
hme0: Ethernet address 08:00:20:d9:1c:68
OUI 0x0006b8 model 0x000c rev 1 at hme0 phy 0 not configured
OUI 0x0006b8 model 0x000c rev 1 at hme0 phy 1 not configured

hme1 at pci1 dev 3 function 1: Sun Happy Meal Ethernet, rev. 1
hme1: interrupting at ivec 301a
hme1: Ethernet address 08:00:20:d9:1c:68
OUI 0x0006b8 model 0x000c rev 1 at hme1 phy 0 not configured

Fri, Jul 12, 2002 at 12:04:14AM -0400, ji@research.att.com:
> In short: the driver sends out packets, but it can't receive. 
> 
> I'm trying to install netbsd/sparc64 on an old netra t1.  Aside from the 
> problem with ifconfig that I reported earlier, I noticed that the driver
> itself doesn't quite work.  It sends out packets (I can see them with
> tcpdump), but it does not appear to be receiving; it does not respond to
> pings, and does not even receive the arp replies to the arps it sends out.
> 
> openbsd-current has the same problem with the driver (but not with ifconfig).
> 
> /ji