Help! Problem w/ Pioneer A06/106D burning CD-RW disc!

Hi all.
I have purchased a Memorex 4x dual DVD burner
I have flash the firmware into Pioneer A06/106D 1.07
Everything will burn except CD-RW.
It can read CD-RW but when put in an empty disc(CDRW),
the DVD burner said there is no disc.

Does any has the same problem?

thanks.