I have a RealTek trl8139 compatible card. it detect find on every level
but somehow does not work

here is relevent dmesg output:
8139too Fast Ethernet driver 0.9.26
PCI: Enabling device 00:13.0 (0000 -> 0003)
PCI: Assigned IRQ 10 for device 00:13.0
eth0: SMC1211TX EZCard 10/100 (RealTek RTL8139) at 0xc4967c00, 00:10:b5:8c:bd:ec, IRQ 10
eth0: Identified 8139 chip type 'RTL-8139B'
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.

i also get a lot of this:
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
ISO 9660 Extensions: Microsoft Joliet Level 3
ISOFS: changing to secondary root
*usb.c: USB disconnect on device 00:07.2-1.1 address 4
*hub.c: new USB device 00:07.2-1.1, assigned address 6
eth1: CATC EL1210A NetMate USB Ethernet at usb1:6.0, 00:10:4c:13:30:ea.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.
eth0: Setting half-duplex based on auto-negotiated partner ability 0000.

*The usb is because i have a usb ethernet adapter wich is setup as eth1 (which im using for now)
now i can do : ifconfig "my_ip" netmask ... broadcast ... up
no error. ifconfig output:
eth0 Link encap:Ethernet HWaddr 00:10:B5:8C:BD:EC
inet addr:70.64.195.83 Bcast:255.255.255.255 Mask:255.255.252.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:134 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:0 (0.0 b) TX bytes:28180 (27.5 Kb)
Interrupt:10 Base address:0x7c00

eth1 Link encap:Ethernet HWaddr 00:10:4C:13:30:EA
inet addr:70.64.195.83 Bcast:255.255.255.255 Mask:255.255.252.0
UP BROADCAST NOTRAILERS RUNNING MULTICAST MTU:1500 Metric:1
RX packets:19553 errors:0 dropped:0 overruns:0 frame:0
TX packets:19618 errors:0 dropped:0 overruns:0 carrier:0
collisions:26 txqueuelen:100
RX bytes:7121676 (6.7 Mb) TX bytes:1750743 (1.6 Mb)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:198 errors:0 dropped:0 overruns:0 frame:0
TX packets:198 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:15353 (14.9 Kb) TX bytes:15353 (14.9 Kb)

but that is as far as it will go.
from there nothing works
dhcpcd eth0 hangs (does not give any ouput but i can kill it)
if have added in /etc/modules.conf the following line
alias eth0 8139too
any ideas is more than welcome
thanks you all

try
#ifconfig eth1 down
which will tell linux not to use eth1, so it will use eth0 instead

It could be that there is a hardware problem (such as a bad cable) or your router is not running a dhcp server.

sorry i should have said:
Here is what i have done:
ifconfig eth1 down
killall dchpcd
ifconfig eth0 ... ... ... up
dhcpcd eth0

also i dont actualy have a router. this is a single computer/connection.
and the cable as to be good cause it is the same that i connect to the usb ether adapter.
Thanks for the tips though