Burning a 700mb cd

I am trying to burn Route66 Route Europe. I am using a 700mb cd but it says that it will not fit and asks me to try overburning which may result in damage to my burner (Sony DRU540). I need to back this up really soon, any ideas?
thanks in advance…
Andrew

What is the size of the original CD?

Ok, I thought my cdrw was 700 but only 650. Now that I got that taken care of I am getting read errors on the second disc only. I found out it is because of dummy files and I dont think my burner supports overburning. I am burning onto 700mb cdr’s but like I said I am getting read errors. How can I get around this problem?
thanks,
Andrew

may i ask why u need to backup it up so soon, Andrew3161?

because I want to take a copy with me on my trip, not the original