I have a JVC GZ-MG135AG camcorder and we suddenly have a problem with the zoom/wide control. It will zoom or pan but will not adjust the focus. It seems only to focus at 2 separate points eg x7 and x19, although this varies slightly for what you are trying to focus on (distance away). I have tried going through the menus to see if changing between manual and automatic has any effect, but it doesn't. Any ideas?

Hmmm it sounds to me like your focus.distance & ranging electronics have somehow gone faulty... that or the Focus Drive, has faulted or both, it is real hard to tell without actually examining the unit.
In any event, it is NOT a setting nor software, it is indeed a fault within the unit, i have seen similar ones before.
You will have to take this camera in for repair, as special tools and software are required to service and repair this unit.
You need to contact a local or head office of JVC, and ask them for a referral to an local to you, Authorised servicing center. Now when you take your unit in for repair. Ask them first for a "Quote" for the repair. That way you can decide as to repair or replace, as this may be an underling symptom of a much greater problem,although i think, that it will be a simple repair,one can never tell until it is on the operating table so to speak. However in this instance i cannot see the repair being all that expensive, as it;s a fairly simple job to replace the faulty bits.