Can't burn data discs - mismatch errors

Hey all . . . newbie question

I burn FLAC files to DVD+R or -R discs as archives . . all going fine, but lately my NEC-3450A drive (in a Dell 8400) will not burn data. When checking files, I get “error_frame_crc_mismatch” and abbreviated files. The drive burns audio fine (at least it seems fine), but will not burn data to a CD-R,DVD+R or DVD-R no matter what brand I try(Fuji,Maxell,Verbatim, TDK . . ).
I updated the firmware for this model, . . . help!! Is my burner just fried? It’s only nine months old, but get a lotta use . . .