guess I should have waited, as I ended up mailing mine in, received by IRS on March 22 (tracked via DHL, mailed from another country), and when I check the Where Is Mah Mighty Fine Refund web page on the IRS site, it can't find my return, and tells me that if sent via paper (not e-file), it could take upwards of 6 weeks to process (or maybe that web page doesn't work for amended returns?)...
