Just my five cents...
On my laptop (Dell Vostro 1310) I get _periodically_ (not always!) the sameerror:

re0: port 0x5000-0x50ff mem 0xf8410000-0xf8410fff,0xf8400000-0xf840ffff irq16 at device 0.0 on pci7
re0: Chip rev. 0x3c000000
re0: MAC rev. 0x00400000
re0: PHY write failed
re0: PHY write failed
re0: MII without any phy!
device_attach: re0 attach returned 6

I didn't notice any regularity of this error. I kldload this driver by hand(most of working time I don't need wired connection), and sometimes I haveto reboot after it due to error described above...
Fell free to ask any additional information, I'll be glad to help!

Information from pciconf:
re0@pci0:7:0:0: class=0x020000 card=0x026f1028 chip=0x816810ec rev=0x02 hdr=0x00
vendor = 'Realtek Semiconductor'
device = 'RTL8168/8111 PCI-E Gigabit Ethernet NIC'
class = network
subclass = ethernet

Running 7.1-PRERELEASE, cvsupped 29th Aug.

Ilya Bakulin

Version: GnuPG v2.0.9 (FreeBSD)

iEYEARECAAYFAkj8Tz4ACgkQo9vlj1oadwh8DACgtAXizlr6OO oAtQPxWsZmvbA4