Hello Eluned,
I have one of these machines so I am sorry to hear you are having problems. Here are a few things to check out.
Are you hanging the cast-on comb on to the stitches after knitting from right to left?
Have you checked the condition of the sponge bar? At each end of the needlebed there is a rectangular gap. If you push a suitable tool into this gap you will be able to remove the sponge bar which holds the needles down in the correct position. The sponge in the bar should stand up above the metal by about 1/4 inch all the way along, if it does not there is not enough pressure on the needles and problems arise with the knitting and the bar will need replacing. Unfortunately there do not appear to be any Toyota sponge bars available any more but the Knitmaster/Silver ones are fairly narrow and do fit Toyota machines.
One other thing to check is that the pattern dial is set to Plain so that it knits in both directions.
Hoping this gives you a few pointers and that you are soon knitting,
Sue
January 2011