Have you tried to use another player...??
I have dvds (store bought) that will play on PowerDVD but not on Windvd and visa versa as well...
btw, Sometimes it's impossible to play DVDs bought in Europe or Asia on an American DVD player or vice versa, due to incompatible copy protection schemes. The issues are endless. Zoom player seems to play what other players cannot...
Maybe try some Region free voodoo
