A silly question...

[jperez]

First at all let me start saying that I have a Samsung SW-252B.

I tried to burn 701Mb to a 700Mb disc (according to Nero this CD had 703Mb of capacity), the recording process had no problems, but, when I try to use that CD windows does not allow me, it gives me a read error.
So, thinking on what I did wrong, I realize that the filenames are quite big, could this be the problem?, I mean, that CD is useless, can I burn that data again to other CD if I change the filenames?

I tested this CD against the Nero CD Speed Test, and when it reaches the 650Mb barrier (aprox.) the speed goes down drastically, is this normal?, I think it is because of some reviews I saw.

Also, for your information and the Media Compatibility lists: On this recorder the Sony 40x discs are limited to that speed (I believe because of JustSpeed) and I had no problems with the same discs but with burning them not at full capacity.

Best regards and thank you in advice.

[jperez]

Sorry, I forgot to say that I'm using the Nero copy that came with the recorder (I'm not entirely sure what version it is)

[dodecahedron]

the slowing down means the CD wasn't burned very well, the drive has to slow down when reading to be able to read the data correctly.
try burning the media at a lower speed, see if that helps.

as for the long filenames, yes that can be a problem.
(i'm not saying it is in your case, but it might).
try shortening the name.
assuming you're using Nero 5.5, in the compilation window the files whose names are too long will be shown in italics, so you should be able to see if some files have names that are too long.
also, before the burn actually starts, Nero should warn you that some files have long names (unless this feature was "turned off". to be sure this feature is "on", click in the menu-bar File -> Preferences, in the General tab the 4th checkbox is "Check Joliet filenames before burning", make sure it is checked).

to check which versin of Nero you have, click in the Menu-bar Help -> About Nero.

[CDRecorder]

You could also try burning at a different speed, such as 24x.