Right, When I first got my new guitar I got it set up to be in Drop D,
It's an Ibanez RG1570 Prestige, and it's got an Edge Pro.

But, I changed the tuning myself to have it in Standard.. But recently everytime i even touch touch the trem to say like.. divebomb.. or knock it out of tune a bit (e.g.. Eruption - Van Halen), my tuning just goes off completely..?

What's the deal with thaat?

I tune it like this..
1. Loosen the locking nut.
2. Set fine tuners to half way
3. Begin Cross Tuning
4. Once i'm done, I tighten the locking nut.
5. Make any slight adjustments with the fine tuners
6. Done?
whenever i change strings i'll always divebomb as far as i can, then lift the pitch as far. and do that over and over. eventually your strings will stop stretching. if it's not that, i'd have to say take it get it set up
Warmoth Telecaster Deluxe. Warmoth Strat. Seagull Artist Portrait Acoustic.

"Well good God damn and other such phrases, I haven't heard a beat like this in ages!"
-Dan Le Sac Vs The Scroobius Pip
Sometimes Floyd Rose tremolos and Floyd clones can be weird until the settle in. Have your guitar looked at by a professional repair tech. It's probably not a big deal.

How many springs do you have in the unit? The extra tension on the "E" string might be enough to require a tremolo adjustment.
have you got the strings clamped properly at both ends (not overtightened though), and what guage are you using i presume 9s or 10s....is the trem level, i`ve never had a stability issue using either of my edge pro equipped guitars, they stay in tune for hours and i use the trem alot especially when i momentarily think i`m vai.
Uhhmm.. Well I tighten the locking nut rather tight, like as tight as I can make it.
using 9s yes. The trem is maybe a few degrees off horizontall (is this a problem?)