[Yum] proxy in yum.conf -- Bad Idea?

[pat_n_cats at juno.com (pat_n_cats@xxxxxxxx)]

I added proxies to the yum.conf file
  proxy=http:nnn.nnn.nnn.nnn:3128 etc
    yum could not connect to repos

setenv   proxy_http,proxy_ftp,proxy_HTTP,proxy_FTP 
   appropriately.
    yum could not connect

used panel->system->preferences->network proxy
    to set automatic proxy configuration
    yum could not connect

Finally after days I removed the proxy=  statements from
    yum.conf  
     yum connects and works !

OS = Fedora-5
hardware = intel 686.
yum-2.6.1
connection > 5MHz

Don't know whether this is just my usual blundering or 
   is a genuine problem; but am passing it on in case it
    helps someone else.  Nor have I bothered to investigate
    which of the proxy definition(s) is/are needed.
 
          Pat