Sometimes, yes.
You see...
These are the write speeds your burner supports with that media. Since 4x isn't resulting in a good burn, 6x and 8x are your next options. 2.4x isn't recommended because that media is rated 16x, and burning too slow in 16x media never gives good results. You could also try with Verbatim or Taiyo Yuden blanks, and you could also join the dark side, I mean, try with DVD-R discs