@pnored -- yeah, ultimately, it seems that reporting it either way seems to satisfy the IRS, even if one has to explain where it was reported on the return. I did find a couple sources, fact-checked by CPAs, which indicate that reporting it on Schedule C, line 6 is what they would do (see here and here), so I think that's where I'm going to report my single member disregarded entity LLC's bank interest (and not on my Schedule B).
