Failed update

[Jim Byrnes]

Three days ago I turned on a Ubuntu 10.04 system that hadn't been run 
for over a month.  Update manager reported 90 updates to download.  When 
it was all done it reported 13 files it could not download. I waited a 
couple of hours and tried again with the same result.  This time I let 
it apply the updates that it could.

Today I tried again and it still could not download those files.  Here's 
a snippet of what it could not get:

W: Failed to fetch 
http://security.ubuntu.com/ubuntu/pool/main/c/chromium-browser/chromium-browser-l10n_11.0.696.68~r84545-0ubuntu0.10.04.1_all.deb
   404  Not Found [IP: 91.189.92.166 80]

W: Failed to fetch 
http://us.archive.ubuntu.com/ubuntu/pool/main/l/linux-meta/linux-generic_2.6.32.31.37_i386.deb
   404  Not Found [IP: 91.189.88.30 80]

In the past when this happened it was usually some type of server issue 
that cleared up rather quickly.  What would you suggest I do to fix this?

Thanks,  Jim