We always used to be able to do network installs without a full set of RPMS downloaded in advance -- if the installer wanted one which wasn't present, it'd complain and its error dialog box would have a 'retry' button. So you could fetch the missing RPM and click 'retry' and continue on your merry way.... It doesn't do that any more. The only option is 'reboot'.
In a lot of cases, we are already retrying multiple times before popping up an error message. We're using urlgrabber which has retry support. However, there's still room for improvement.
Retrying before you pop up the dialog box which tells me which package you want me to fetch and add to the Fedora/RPMS/ directory isn't going to work. You need to tell me what you want and _then_ retry after I click the 'retry' button (which doesn't exist any more).
*** Bug 191301 has been marked as a duplicate of this bug. ***
This should be much better in FC6t1 and later.