If you do run into further problems with the media... there's basically three main reasons your media would be stuffed.
* the download: wget is pretty much the most reliable method of downloading error-free known to man, torrents are another good way to go.. since most of them allow you to check the completed download for missing chunks.
* the burn: the conventional wisdom is to burn at a low speed, some burning programs calculate the md5 sum and check against the completed cd.
* the media: not all dvd/cds/etc are created equal.
EDIT: forgot the md5/sha bit
After you've leeched the iso, you can download the md5sum or sha1sum files from the server.
You then compare it to the downloaded iso like so:
lashni@orphan pardus $ md5sum -c Pardus_2008.1_Hyaena_hyaena.iso.md5sum
lashni@orphan pardus $ sha1sum -c Pardus_2008.1_Hyaena_hyaena.iso.sha1sum
If the response is anything other than OK, the download is corrupt or incomplete.