Unable to read CDs

I'm new to this, but i was wondering what determines if some other user can read my cd if i burn. Sometimes i burn a cd for my friend, they can't read it, but when i burn it at a lower speed, they can read it. So question again is what determines the ability of other users reading the cd? CDR brand? CD drive? Burn speed? ??? ?

Thanks for all your help!

What's important in 1st place is your writer! A Plextor1210 fe has a stronger laser then Mitsumi4802! So if you burn 4x with the Mitsumi you may come to the prob that your audio cd isn't workin!! And when you would burn the cd with the Plex @ 12x, you will see that it works great!
This is only an example cause it (offcourse) won't go wrong every time! (but I've experianced it! )

Also is the brand of cd's important!! Blank cd (no label) won't work in every drive!! (experianced this also!! :mad: )

So if your not sure if your cdwriter is a very good writer just lower you burnspeed (audio only); with my Misumi I always burned @ 4x but audio @ 2x!!!
And I never use blank cd's!!! (only with label on it!)

Good luck!!