How can i fix the needle holder in a toyota jeans sewing machine?

Hi, have been sewing all afternoon - with no problems, changed needle to a jeans one and then when i have finished job was changing the needle to a ball point but the other needle was really jammed up and i had to use pliers to get it out. Now i can't put in another needle? There was no problem/jamming/noise on previous sewing job?!Have had a look and hole seems fine - as though something stopping needle going in.
Confused!