Burn good Verbatim Mitsubishi-made 16x media (MCC004 DVD+R, MCC03RG20 DVD-R) at 8x or 12x. That's the optimum speed to burn a 16x disc anyway.
The best burn on 8x media is often achieved at 4x-6x, not 8x.
TDK is generally pretty mediocre media these days, all being budget-grade RITEK or CMC discs that don't always burn well. There are generally more coasters in a pack (10-20 maybe, on average, out of 100 discs burned and tested) while Verbatim/Mitsubishi discs burn near perfect (maybe 1-2 bad discs in a 100-spindle).
TDK Gold CD-R, sold in Australia, have long been CMC discs that give dismal results. I wonder what the media ID is on these TDK DVDs that you're using? I'd bet on CMC, RITEK or maybe MAM-A.
See what you have. If you don't know how to read a media ID, then see this post: http://www.digitalFAQ.com/forum/show...ia-id-393.html
The one variable that may be an issue, however, is that LG drive. Quite a few LG drives, starting around 2006, began to burn Verbatim discs poorly. Sometimes it's just a matter of needing a firmware upgrade. Sometimes the drive model just doesn't work well with Verbatim (MCC/MKM). I've had 3 of these drives. But because I wanted to use the best discs available, I just spend $30 or so to replace it for a better Pioneer, Samsung, Sony or LiteOn drive.
While keeping that in mind, go ahead and still try the Verbatim discs. Long-term, that would be a better solution than 8x on marginal-quality 8x discs. Even 16x on a good Verbatim disc would be preferred to 8x on a sub-par disc.