If I'm taking 72t distributions (pre 59 1/2, Substantially Equal Series), can I take out $2,500 and still use the 60 day rule on a onetime distribution if I redeposit it and not "interupt" my normal SES distribution? Thanks

Probably yes, but if you miss the 60 days, you've screwed up the entire payout series. Is it worth the risk?

I'm no expert on this, but I would almost swear I remember that the Arnold case came to the conclusion that an additional withdrawal triggers the penalty. And although I can see your argument that it doesn't really constitute a "withdrawal" if it is rolled back in and is not subject to taxation, would you feel comfortable that this is a strong enough argument to prevail if the IRS challenges it? I'm just curious because I received a similar question last month. Thanks.

Arnold did not involve a 60 day rollover question. I think there is no problem because if it's rolled over, it's not considered a taxable distribution. However I have to speak to the IRS in DC tomorrow, and I will try to remember to raise this question.