Here we go again! Is this a new condition? Meaning, did you ever have a machine that was functioning properly? Can you make a video of the problem? Do you have a nearby friend with a Deus or a dealer so you can swap out components to troubleshoot? Troubleshoot until you give up--this includes reloading the software and making sure you're familiar with the start-up procedure (there's plenty of discussion about this on this site). This link may help you to decide what and what not to do: http://www.findmall.com/read.php?83,2135887,page=1
If you get no relief, then contact XP and see if they have any solutions for you. Finally, if they tell you to send your machine in, be sure to send everything: the coil (not the shaft), the remote and headphones so they can properly troubleshoot the problem. If there's a problem, they'll find it. FYI XP will upgrade their return shipping at your expense; all you have to do is ask. Good luck!
EDIT: Some things to ask yourself:
Ensure there's nothing between the coil and the coil cover.
Are you using the provided nylon screw/nut to attach your coil to the shaft?
Do you have any aftermarket items attached to the coil or shaft or arm cuff?
Are your shoes the cause of the problem...any metallic materials involved in the construction, i.e. steel-toed boots? Metal socks, metal pins in your legs from surgery?
Do you have hearing aides that may affect the Deus signal?
Any metallic items associated with the gloves you use?
Do you use a huge belt buckle?
How about your belt with gear...anything on, or in there that may cause interference?
Do you carry a longer shovel to dig with like some hunters? Keep it clear and definitely discard it when you're turning on the machine.
Are you using version 3.2?
Try going to a large field or to the woods where there's likely no EMI.
Leave all cell phones, pagers, radios, video cameras, other detectors, etc. behind and turn off any pinpointers you may be using.
Do you turn the machine on with the coil in the air at least waist high away from cars, powerlines and any other metal?
After you turn the remote on, do you wait for the light to stop blinking before you answer yes or no to audio? (This is what I do).
After your audio selection, do you keep the coil in the air and then turn on your headphones and wait to hear audio in the headphones before putting the coil on the ground? (This is what I do).
Next is when I select my program--have you tried selecting a purely stock program with no modifications, i.e. Basic 1? Does that produce the erratic behavior? If so, the sensitivity is quite high in Basic 1 (90); try reducing to 80 and see if that helps.