Nero 5.5 .iso issue

[TOCSYS]

I just downloaded the 3 .iso files for Mandrake Linux 10.0 from the Rutger's FTP server in NJ. I'm using Nero 5.5 to burn the images to disk but Nero is telling me the media I'm writing to does not have enough space. The blanks I'm using are 80min/700 MB and the .iso files are no larger than 695MB each. I tried several blanks just to make sure that the one I was using wasn't bad. I also upgraded to the newest firmware revision for my Lite On burner (LTR-40125S). Is there something I'm missing? Is there any way I can force Nero to write the .iso files to disk anyway? Any info would help. Thanks.