Oh I see, you are saying that the iftab lists it as eth1? (You never mentioned what was in your iftab, so I didn't realise)
hmm... that's strange, the iftab file should define what the device is actually called based on the MAC address. So as long as it says eth1 in the iftab, and the MAC address is correct, then you should only get eth0 and eth1 in your ifconfig. Check the MAC address is correct.
If that is all correct, then I don't know why it is ending up as eth4. The only other things I can suggest are, once again, you need to look through the log files I listed, after rebooting and look for ethernet related errors or warnings. And finally, search the forums for my postings on udev rules, and set this up on your system - NOTE: udev rules are case sensitive for the MAC address.