> I had the same problem with my laptop dell Latitude. It has a integrated 
> "ex0" ethernet card.
> The netcard device caused timeouts with NetBSD 1.5.2 and it didn't work
> 
> I have upgraded to NetBSD 1.5.3_RC1. Now the network card works ok and 
> very stable.

Thanks for your answer.
I've seen the improvements which has been made up till now
and to the ex code. However, these changes didnt affect the 3c575c-tx card
which i have. I've tried the 1.5.3_RC1 and im still facing the same problems.
I've just filed a pr about it.
Bye,

Mipam.