Brand name means nothing in DVD's. Nearly all brands outsource production to manufacturers. The manufactures use a Media ID written on the disk to identify who made the disk. So run some of your blanks through this http://dvdidentifier.cdfreaks.com and let us know the media code.
You should use Taiyo Yuden discs. They are top of the line discs, and they really aren't much more expensive than "budget" media. I get mine from SuperMediaStore.com for $21.50+shipping for a spindle of 50 ($29.00 total). Best Buy usually runs a sale on Verbatim, which is also top notch, every other week if you don't wanna do the online thing.
There is also Sony and Maxell, which you can pick up in most "brick and mortar" establishments at a good price on sale. Most here will tell you that when you buy media in traditional sores, to look for "Made in Japan" (MIJ) near the barcode and to stay away from media "Made in Taiwan" (MIT). This is a general rule of thumb with Verbatim being the exception to the MIT theory...