If you bought those I hope you saved your reciept.
Return them and buy some quality media. Ritek G-04 "braned" or Verbatim "datalife". If you don't you will be back because your discs are "stuttering" and or "freezing" partway through the movie. That is classic signs of cheap media.
For best bang on the buck I used, Ritek and Prodisc and never have problem.
Tayo Yuden, Mitsui are good but too much $.
The brand you specified I never hear it before.
Doesn't sound like a +/- issue. Sounds more like a media quality problem. Heres a link to a good media guide. Btw I prefer ricohjpn01. I just got a 100 pk from newegg for 34 cents a disc. Excellent media super price.