Sorry my first bit is off topic but I'll get to your question.
Are you using the NDSGBA emulator? How did you get that to save? Did you have to patch it or do anything special?
I'm having trouble with FR/LG and RSE, trying to get them to save. I'm going to try different roms soon, after I get thourgh some school work.
Okay now your question; sometimes when playing Fire Red(FR), if I go into fast forward and then out of that mode, the sound sounds crappy (for lack of a better term). The solution I've found is just... can't remember which one... but the emulator's option screen you can pull up on the bottom screen, there is one tab/section (I think it might be the same tab/section for the fast forward, sorry my ds is @home can't check) that has a sound on/off option. Turning the sound off then back on fixes it for me.
Hope that info helps you.