DVD & video card problem

[inkafone]

Have a cinemaster hardware player which is linked to a Diamond FireGL1000 but when trying to play a DVD get the message "your resolution is not correct",have tried several different settings but same message. The OS was W98 but have now tried Win-ME and now get the message that the video card does not support DVD - do some older cards not work with DVD players? - the cinemaster card was OEM so no
instructions other than the driver CD. Any help appreciated - am in UK.