[ubuntu-uk] no wired network after Lucid upgrade

[mac]

I've just upgraded my Dell 6400 laptop from Karmic to Lucid. 
Previously, if I wired the laptop to the router, it would use the wired 
connection by default, ignoring the wireless NIC;  without the ethernet 
link, it would default to wireless.

Since the upgrade, there is no wired connection at all.  Searches 
indicate there have been issues with Network Manager in Lucid;  but I 
have not found any info that helps me restore the wired connectivity of 
my laptop, and the default selection of the wired connection when available.

If anyone here has encountered and solved this problem, I'd be grateful 
for advice.

TIA

mac