Downloaded the image from your ftp site and it didn't pass the linux mediacheck.
If it passes MD5sum and not mediacheck, then I'm afraid it's your CD writer, although you did say you'd tried two different ones, so I don't see why? My disc 2 does pass mediacheck as does (presumably) everyone elses, so it's not an inherent problem with the iso itself.
Trev
-- Trevor Barton Isotek Electronics Ltd., 9 Clayton Wood Bank, Leeds, LS16 6QZ, UK. Tel: +44 (113) 275 1339 Fax: +44 (113) 224 9827 Web: www.isotek.co.uk Views expressed are my own and not necessarily those of Isotek Electronics Ltd.