red cross and replay gain queries

[woobag]

What does a red cross in the file properties mean?
Can't find any reference in the help topics.

Also, having trouble with replay gain. I don't quite understand the way it works. I have analysed all my tracks but replay gain has no effect. I notice that the peak level is not always 100%, should it be?
The replay gain figure is always a negative db figure. Is 0db the reference point? As the tracks all have a different replay gain value, surely increasing this value say by 5db, will just increase the volume overall, leaving some tracks still quieter than others?
I hope you understand what I am getting at!

Simon

[dmt1]

Red Cross: check the file type--it's probably an mp3 file that's got a problem, or a file type that's not supported by the ipod--ie WMA.

Replay gain increases the volume. The volume is leveled by the option above it--so there are two parts to it when you synch--if you don't level the volume, you could use the gain to increase the maximum loudness, but the goal is to level the sound AND have an adequately loud maximum volume--that's what we're shooting for, and it's a work in progress...