...her player is picky, or maybe a little of both. I've got a DVD/CD burner in one of my computers which burns DVD's fine but doesn't burn music CD's worth a darn. (There are no errors during the burn, they just a good quality burns.) Some CD players will read & play them well, others don't. (You might try the CD's in another player. Sometimes, the player is finicky as well.) So, when I want to burn a CD, I use a different burner which makes better copies and they are read well by all players.

Hope this helps.