They're compatible in terms of work speed/flow, but 30p to 24p is generally fairly ugly.
24p goes half decently to 30p.
I'd create a 30p timeline and upsample the 24p to 30.
Unless terribly desperate, I wouldn't take the 30p to 24p.

Convert it all to 60i and edit on a 60i timeline?

You could try using better tools outside of Vegas to convert 24p to 30p but it isn't entirely goof proof and render time are going to be significant if there's a lot of material to convert.

Bob.

because it's HD I have no ideas. If it was SD I'd say put the 24 fps to DVD & then hook the DVD player up to an analog/digital converter & record it on your camera via firewire & 29.97, but that's not an option here. :(

"Convert it all to 60i and edit on a 60i timeline?"



could you please give a tip as to what settings / how to?

You can convert 24p to 60i by adding pulldown, just search the help for "pulldown" on how to enable this.
You can convert 30p to 60i by simply rendering it out to 60i.

I have to point out that neither of those processes change the original frame rate, there will still be a mismatch in how motion looks between the two different sources. Only way to know is to eyeball the result. What I'm suggesting would be fairly simple to do and give you a smooth editing experience as as far as Vegas is concerned it's all just vanilla 60i.
You may strike some issues with some displays though. Some HDTVs may attempt to do a pulldown removal on the 24p video contained in the 60i and then get confused when you cut to the 30p originated material. I've never tried this and as I don't live in NTSC land don't have easy access to the gear to test the outcome, it might be fine or not. Test, test, test!

If (big IF) you had the budget probably best to pay a post house to run the footage through a hardware converter and get it all the same frame rate. Second very best option is some of the expensive plugins in After Effects or even AE's native time remapping. I think VDub or AVISynth can also handle this task. Just how much effort / money can be spent on this is really the question. I guess if there was a real budget though the problem wouldn't have arisen in the first place although I've come across productions with large budgets that have created similar grief for themselves.

Bob.

If you've ever uploaded a 24p project to Vimeo or Youtube, you've seen a 30p render of 24p. Like Spot says, it isn't horrible but having just experienced this firsthand on my last project I'm sticking to 30p in the future.