[Gilbear]

Bunch more questions - How big are your work pieces? Are you clamping them to the miter fixture? Sounds like you had the miter fixture by itself, without a fence? With the miter alone it would be pretty hard to keep your workpiece from moving - even if clamped - the bits gonna pull it. (Also, if you're trying to hold the workpiece with just your hand against the miter, seems a little dangerous as the bit's pulling you towards the cutters). If your dados or rabbits are along the edges, why use the miter at all - rather than just the fence and a push block? If in the middle of the workpiece, why use the table instead of a guide on the workpiece itself? Quick thoughts anyway.

 

[Gilbear]

So you're cutting a series of roughly 3/4" wide dados across 5" wide stock? Like you suggested, I'd clamp both sides together edge to edge to keep them aligned - I'm not very fancy so I'd just use a 1/2" straight cut bit - depending on how many dados I was cutting, I'd either make a quick and dirty jig that allowed for my base plate and bit size to get my dado width (you need to clamp one edge of the jig at first while testing for dado width fit, and then peg it solid) and plunge cut them, or if not too many of them, I'd simply use an edge guide. I've made an edge guide for the bits I use most often for dados (1/2" & 3/8") that's nothing more than a straight 1x4 on top of 1/4" mdf that I've trimmed off with the bit so the edge of the 1/4"mdf is exactly where the edge of my cut will be.
Not sure what the "ClampEdge" is, but if it's one of those straight edges with the clamping mechanism that slides along underneath, I have one from Rockler and use it constantly - as an edge guide for routing or for a circular saw.

 

[Gilbear]

And yes, the Clamp Edge is the device Rockler has. I planned to order it and am happy to hear you say you use it.

Just a thought on the clamp edge - I use it all the time, but really don't get the cute ruler they've put on top - it's been totally useless for me cause it sits so high above your workpiece and so far away from the edge of the bar - if they'd drop that useless feature they could lower the price a little.

Another way to cut those dados, as an afterthought, is to use a piece of the shelf material on edge as a width guide (remember, nothing is ever truley 3/4" thick), clamp a guide on both sides tight up to it and then cut it with a flush trim bit with a bottom bearing. Let the cut depth of the bit determine the thickness of what you use for guides so the bearing will ride them without going too deep. Million ways to skin a cat ... hmmm, wonder what the going market rate for cat skins is?