A few tips:
-Make sure the tremolo sits flush on the body. Any float or flutter to the bridge makes the D-Tuna unstable.
-Make sure the "E" string is stretched out and locked with the fine tuner about 80% out.
-Tune the "E" string to pitch. When you pull out the D-Tuna, use the small set screw on the side for fine tuning adjustments. Go back and forth between E and D to check tuning. Although this may be the most time consuming part, it is the most crucial.
like stated - stretch out the strings and make sure the trem is flush with the body. tune the low E string to D with the D-tuna in the out position using the tuners (not the fine tuners) and push it in and tune the "E" pitch with the set screw on the side of the D-tuna. your intonation must be accurate as you will never get it right otherwise.
this should work great as i have to adjust Wolfies a lot - i work for a Peavey dealer and this is how the Peavey shop advised me to set it up.
It's my bandmate's guitar so I'll forward this message to him later.
We use regular D tuning (lo-hi D-G-C-F-A-D), and could this make any difference, because when the guitar is tuned perfect to D- and drop the E string to C, the other strings goes sharp. The E- string kept it's tune to C, perfect.
I stretched all the strings, like I do to my Ibanezes, and tightened the springs, and that helped a lot, but still there was a raise about 10-15 cents on the rest of the strings, when dropping the e string.
If all the other strings go sharp when you engage the D-Tuna, I'd bet that the trem is floating somewhat. Bring it flush to the body and all your problems will be solved. Make sure the trem is level to the body, and think about adding an additional spring(s) if you run out of tightening room.