It was a dual-layer DVD-Video press retail disc, and you'd need to burn it back to Verbatim DVD+R DL media. Or shrink it with DVD Shrink, although there could be quality loss. (Knowing the topic of your DVDs, quality loss is very likely!)
B&W video quality on the DVD player would indicate an inability to play PAL DVDs. Finding players that will
not play PAL are more rare than ones that do -- at least in 2009/2010. You'll maybe need to consider buying a cheap $30 Magnavox from
Walmart.