I'm guessing you're talking about the little yellow triangle "rate" slider. That only affects preview from the timeline. It has no affect on anything else at all, ever.

If you want to slow down the output then you have to adjust what's on the timeline. Right-mouse-button click on the event on the timeline and choose Properties. Change the Time stretch / pitch shift method to Classic. Click Lock to stretch, then type in -1.07 for the pitch change. This will slow it down to (almost) 94%

So you're saying that I can't micro manage % of slowing down? -1.07 makes no sense if I want it at 94%, now -1.06 might, but I have found several very inexpensive products that will do this much easier than Vegas. In fact, why would they have one way to slow things down to preview but an entirely different way to actually slow it down? That is just really not logical. They reinvent the wheel to do the same 2 tasks? Why not just have a way to say when use use the Rate option in the lower left hand corner that says "Make this change permanant for this project."? That would be logical. What they have now makes 9.0 look like a v1.0 product.

Perhaps it's time to look elsewhere for a more mature product.

You're not understanding what the rate slider is for. It simulates the scrub control found on videotape editing decks. It's purpose is to let you 'scroll' forwards and backwards across the material at fast or slow speeds to quickly locate the exact edit point you are looking for. That's it's only intended purpose. It's not intended to affect the material on the timeline.

As far as -1.07 instead of -1.06, that's because the pitch change is in semitones. Each semitone is a factor of 1.059463094 (2 to the 1/12 power, since there are 12 semitones in an octave). Subtract one semitone results in a speed of 94.3874312%. You need to subtract slightly more than 1 semitone to hit 94% exactly. -1.06 semitones would result in 94.0608755%. -1.07 semitones would be 94.0065595%. -1.08 semitones would be 93.9522749%.

Then the slider bar is usless on high resolution monitors becuase it jumps in such large intervals.

As for the semitones, that's all well nice and good but if what you're editing just needs to be slowed down by a very specific % then there's NO reason why they couldn't have it. For example, if a piece has to fit into an exact period of time. Ask a trombone or violin player if they can play a note half way between a C and C#. Pretty much only a keyboard player has limits on what notes they can play, but wind and string players can play any pitch they like. In the end, I've decided to use a much less expensive shareware tool that has 10x more options including both semitone and % control over music. When Vegas gets the tools I need I'll look at it again.

Try this:
1) Right-cllick on an audio track
2) Select properties
3) On the Audio Event tab under "Time stretch / Pitch shift" change Method to "Classic"

Is that what you're looking for?