No sound under the F1-F5 keys

[gudata]

Hi,
I have all sounds working except that when I press some of the action keys F1-F5 they doesnt produce any sound. also I cant hit any coming note.
I expect to here at least the "broken" sound but nothing.

here is what I know for my system: del optiflex 320 with Soundblaster Audigy Digital, Windows XP,
Because I am using external decoder I have tried to turn it on/off but it is the same case - no sounds when I press the keys.
Suggestions ?

[pimpinpalomo]

first, do you even know how to play? you hold the key matching the note coming up, then you push the strum button as it passes the fret.
second, pushing the F1-F5 keys doesnt produce a sound. pushing the F1-F5 keys will only light up the frets. if you strum when you are holding the wrong fret or when there are no notes, the "screw-up" sound will play and the guitar track volume will be lowered.
third, is the song even playing? do you hear the song even before any notes appear?
also, are you using stock FoF or a mod?
you havent given enough information for us to help.