i would notice that with my floyd rose, after using the tremolo bar for some time (10 minutes) some of my strings would go out of tune

ive heard people say things like "it'll take all the force u give it and will never go out of tune

ive locked the nut and put the strings in correctly so i figured it had to be something else

could it have been strings that are too thin??

old strings?

something i'm missing here?
old strings are more likly to go out of tune. Also look at your guitar side on and see wether the bridge is level with the body. If it isnt then you need to take of the back panel and there should be 2 big screws an you have to adjust them.
Current playing with:
Cort x-6 -->Laney HCM65R

On Zakk Wylde's guitar.
Quote by anaoshak
look at all those knobs, he must have a mean tone.

Quote by Joey Walker
Bottle caps buddy, they are bottle caps
Well, i usually make a little check list in my head. Make sure the nuts are tight, make sure that the strings are fully stretch (even though the strings from the nut to the bridge may be stretched the spot from the nut to the headstock may not be). But your intonation may be off to, if you change the strings to a different size the intonation may be out of whack. So you may have to take it to a professional and have it looked at.