This is the same problem we experianced with SL 6.0  in August 13. ( Two years 
ago ). - the comm chip set is not broken.  Run ifconfig and you can see that 
it Receives data but no transmit.   
SL 5.10 works. 
SL 6.0 and later versions have a mistake in driver and kernal, are  broken..

We used a ELRepo kernal and driver to fix problem with SL 6.5.   It has worked 
well for 2 years.

We gave up on SL 7 ect. for a server / back up.  We just purchased a raid box 
with 10 slots and it uses Linux with a wonderful clean and logical desk top.  

For other boxes in plant we decided drop back to SL 6.7 which works pretty 
well.  But no Ethernet as in SL 6.5.

Looking for an Elrepo driver and Kernel to fix problem.   There is not a set 
for SL 6.7.   Anyone have any idea when we might see the driver and kernel.

When I am looking at complaints with with install problems the Ethernet 
problem may contribute to a lot of these unhappy campers.
It is too bad the upstream vender did not fix the problem up front. It would 
have saved a lot of people a lot of fooling around. 
Leaving broken problems unfixed is a mistake and just conpounds the orrig. 
error.  As the versions move along and the number of users expands things 
just get worse.   

Thank You
Larry Linder