Can’t get ebayomatic to return posts reliably

Hi, first problem is that I'm using ebay UK, and the category structure for Motors is completely different to ebay US (Which is what the plugin is showing). I have tried to get around this by using the numeric category ID (eg 9801), and the same search criteria as I would use in a search, eg "Mitsuoka".. However, I either get no posts returned, or a load of garbage posts with no relation to what I asked for.. What am I doing wrong?