It seems like I have stirred up a bit of a wasps nest with this question.
It says in the manual that the cable should be from the camera to the autoguide socket on the mount. As far as I can recollect the manual for the EQ6 says that it is ST4 compatible, which should be fine.
Thanks for all the replies to this thread, I'll check out suggestions etc tonight. As you can imagine it is driving me nuts because I really need to extend my exposure times to get better results.
