Subject: Re: How true is this?
Well, sure, but the "high" crimes still have to have been committed while currently in the office as pres or veep, right?

I don't think the Constitution requires that. If a public official commits an act of public corruption while holding federal office, and then assumes a different federal office, I think the Congress would probably be able to impeach them. I think that's consistent with the provision that allows them to impose a prohibition on the person holding any federal office, not just the specific federal office they were impeached from.