eMac external dvd problem



Got a bit of a problem with a DVD drive (Samsung SD616) in an external ide to usb case (Genesys bridge I think). It's connected to a 700Mhz eMac with 256Mb RAM and OS x 1.5.1. Finally persuaded to make Apple's software DVD player to work with a patch (it didn't recognise the hardware before this). Out of four DVDs tested, only one plays without 'jerkiness' and dropping frames.
Is this a problem with the speed of the processor, or the usb connection, or software?
Any thoughts/help from anyone would be appreciated, cos I'm not particulary knowledgeable about macs....

Cheers :)

Shop Amazon

Shop for your Apple, Mac, iPhone and other computer products on Amazon.
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.