Video playback stuttering with Elgato EyeHome



I have been using an Elgato EyeHome to play back TV recordings from my MacMini (G4 1.33GHz) through my TV. It has always had a problem in which the video 'stutters', but more recently it has got a lot worse, almost to the point of the recordings being unwatchable and I cannot find any apparent reason for it to have got worse.

I have run a Cache cleanout on the computer in attempt to solve the problem - this has made the computer itself a bit faster, but no effect on the EyeHome playback. The recordings are stored on an external USB 2.0 hard disk (connected direct to the computer, not through a hub). The EyeHome is connected to the network via the supplied wireless bridge, and the MacMini is connected directly to the base station through the LAN port.

Does anyone have any suggestions - is it likely to be a problem with the Mac or the network? I have updated all of the EyeHome software etc to no effect. Any suggestions would be much appreciated.