Same problem.  I can connect to the internet fine, but I cannot change any details about this interface using Network Tools.  Tried using 2 different nic's.  Running a fresh install of 8.04.

lspci -v:

01:09.0 Ethernet controller: Linksys Gigabit Network Adapter (rev 10)
	Subsystem: Linksys EG1032 v3 Instant Gigabit Network Adapter
	Flags: bus master, 66MHz, medium devsel, latency 64, IRQ 17
	I/O ports at a000 [size=256]
	Memory at fb005000 (32-bit, non-prefetchable) [size=256]
	[virtual] Expansion ROM at fa000000 [disabled] [size=128K]
	Capabilities: [dc] Power Management version 2

00:14.0 Bridge: nVidia Corporation MCP51 Ethernet Controller (rev a3)
	Subsystem: Giga-byte Technology Unknown device e000
	Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 20
	Memory at fc007000 (32-bit, non-prefetchable) [size=4K]
	I/O ports at b000 [size=8]
	Capabilities: [44] Power Management version 2


uname -a:
Linux fadebloom 2.6.24-16-generic #1 SMP Thu Apr 10 13:23:42 UTC 2008 i686 GNU/Linux

lsmod:
Module                  Size  Used by
ipv6                  267780  10 
af_packet              23812  2 
rfcomm                 41744  2 
l2cap                  25728  13 rfcomm
bluetooth              61156  4 rfcomm,l2cap
ppdev                  10372  0 
powernow_k8            16704  1 
cpufreq_stats           7104  0 
cpufreq_userspace       5284  0 
cpufreq_conservative     8712  0 
cpufreq_powersave       2688  0 
cpufreq_ondemand        9740  1 
freq_table              5536  3 powernow_k8,cpufreq_stats,cpufreq_ondemand
video                  19856  0 
output                  4736  1 video
dock                   11280  0 
sbs                    15112  0 
sbshc                   7680  1 sbs
container               5632  0 
battery                14212  0 
iptable_filter          3840  0 
ip_tables              14820  1 iptable_filter
x_tables               16132  1 ip_tables
ac                      6916  0 
sbp2                   24072  0 
parport_pc             36260  0 
lp                     12324  0 
parport                37832  3 ppdev,parport_pc,lp
snd_hda_intel         344728  3 
snd_pcm_oss            42144  0 
snd_mixer_oss          17920  1 snd_pcm_oss
snd_pcm                78596  2 snd_hda_intel,snd_pcm_oss
snd_page_alloc         11400  2 snd_hda_intel,snd_pcm
snd_hwdep              10500  1 snd_hda_intel
snd_seq_dummy           4868  0 
snd_seq_oss            35584  0 
pcspkr                  4224  0 
snd_seq_midi            9376  0 
snd_rawmidi            25760  1 snd_seq_midi
snd_seq_midi_event      8320  2 snd_seq_oss,snd_seq_midi
snd_seq                54224  6 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_seq_midi_event
evdev                  13056  3 
snd_timer              24836  2 snd_pcm,snd_seq
snd_seq_device          9612  5 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_rawmidi,snd_seq
snd                    56996  17 snd_hda_intel,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_hwdep,snd_seq_dummy,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
k8temp                  6656  0 
sr_mod                 17956  0 
cdrom                  37408  1 sr_mod
soundcore               8800  1 snd
nvidia               7825536  34 
i2c_nforce2             7680  0 
agpgart                34760  1 nvidia
i2c_core               24832  2 nvidia,i2c_nforce2
shpchp                 34452  0 
pci_hotplug            30880  1 shpchp
button                  9232  0 
ext3                  136712  1 
jbd                    48404  1 ext3
mbcache                 9600  1 ext3
sg                     36880  0 
sd_mod                 30720  3 
pata_amd               14212  0 
usbhid                 31872  0 
hid                    38784  1 usbhid
pata_acpi               8320  0 
sata_nv                27528  2 
ata_generic             8324  0 
floppy                 59588  0 
libata                159344  4 pata_amd,pata_acpi,sata_nv,ata_generic
ohci1394               33584  0 
forcedeth              51980  0 
ieee1394               93752  2 sbp2,ohci1394
r8169                  32900  0 
scsi_mod              151436  5 sbp2,sr_mod,sg,sd_mod,libata
ohci_hcd               25348  0 
ehci_hcd               37900  0 
usbcore               146028  4 usbhid,ohci_hcd,ehci_hcd
thermal                16796  0 
processor              36872  2 powernow_k8,thermal
fan                     5636  0 
fbcon                  42912  0 
tileblit                3456  1 fbcon
font                    9472  1 fbcon
bitblit                 6784  1 fbcon
softcursor              3072  1 bitblit
fuse                   50580  5