Description of problem:
At work we have a odd network setup -- we can connect via http-protocol only
over a squid proxy (e.g. outgoing via port 80 is blocked for normal systems).

No big deal as such, but I also have internal repos, which are not accessible
for the proxy. Thus I configured yum to not use the proxy for the internal repos
-- seems that is not honored when fetching metadata.

Version-Release number of selected component (if applicable):
yum-3.2.2-1.fc7

How reproducible:
Always

Additional info:

My repo-file:
---
[internal]
name=internal -- generic 
baseurl=http://foo/pub/repo/generic/$basearch/
enabled=1
proxy=_none_
metadata_expire=1
gpgcheck=0
---
# export http_proxy=http://squid.domain.de:8080
# yum update --disablerepo=* --enablerepo=internal
Setting up Update Process
http://foo/pub/repo/generic/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error
503: Server: squid/2.6.STABLE5
Date: Fri, 31 Aug 2007 08:00:48 GMT
Content-Type: text/html
Content-Length: 912
Expires: Fri, 31 Aug 2007 08:00:48 GMT
X-Squid-Error: ERR_DNS_FAIL 0
X-Cache: MISS from squid.domain.de
X-Cache-Lookup: MISS from squid.domain.de:8080
Via: 1.0 squid.domain.de:8080 (squid/2.6.STABLE5)
Proxy-Connection: close

Trying other mirror.
Error: Cannot open/read repomd.xml file for repository: internal

# unset http_proxy
# yum update --disablerepo=* --enablerepo=internal
[works as expected]