best advice.
second best advice could be to try a fast Lexar CF card of some type. 1000x at a minimum.
note: I have a personal gripe against Sandisk cards as they always seem to let me down .. and usually at the most inopportune times!
According to Rob Galbraith tho, Lexars fast CF cards seem to work better inside a D800 series, then Sandisk cards do.
I get about 15 shots in a burst on my D800E and I'm only using a fast-ish(ie. not the fastest!) 800x Lexar CF card.
(note that I don't use jpg mode at all, only raw mode).
Recovery time isn't too bad. My camera doesn't lock up .. as such .. but does need about 10sec or so to recover to a point where you could shoot another 2 sec burst at 4fps.
Keep an eye on the 'r' number when you half press the shutter. Camera with an empty buffer will show an r12 value both through the viewfinder and also on the top LCD when you half press.
This value is the buffer's remaining image allowance.
So at the start, it will show you what it thinks the buffer can hold in a burst. If you shoot at the max 4fps mode, this number will reduce in real time to show you how many shots you have left before it slows right down to about 1fps or so.
So about half way through to the approx 15-17 max continuous shots in one long burst, the R value will drop, rise again by one integer again for a moment, keep dropping and then rise again. That increase in number(eg. r06 -> r07) just means that the buffer cleared an image and there's room for one more shot.
So after about 10sec or so, you should have about an r08 or so allowance(as per above).
there could also be the possibility that your Sandisk card is fake.
or that's it's less compatible with the D800, than say a Lexar seems to be.
You could try a faster card, and make sure that by faster it's not just the read speeds that are fast.
Reads speeds on cards ratings are generally not that useful, it's the write speed that more important for most uses.
It looks as tho the D800 series seems to top out at about a 70-ish Mb/s write speed, so if you get a card capable of being written too at say 80-100Mb/s, you've probably maxed out what little performance that the D800 can muster.
Any more speed above that point will only be wasted, unless you have very little time when transferring to a computer too.
But .. like Rick said, learn to be more selective about WHEN you use the spray and pray technique. It should be remembered that the D800 was never designed to be a speed camera. That's why Nikon had the D4 camera model!