problems installing 2.1 with Tetex.bin

After having flirted with Beta3 & failed to get it to do what I want. I am trying to re-install the stable version. It fails every time at installing Tetex.bin. I have burnt 2 dvds (having checked them against the md5 sums) & re-formated the disc & increased the size in case that made a difference. I am using the same machine/disc (AMD64) as before I hosed the system with the beta3. The log file is pages long & I can, with difficulty, probably get it off the machine & forward it if it helps, the only thing that looked problematic was a line in the log file that said tetex.bin was over 5 years old. 1) any ideas to fix the issue or bypass it? 2) can I install the 2.0 version from the live CD? (& perhaps then upgrade) 2.1 is the version was running before so I feel it is not something intrinsic to the machine. Steve