I've been at this a few days and gotten... nowhere. I have one product file that won't import. As near as I can tell, the issue is around line 476. The same layout/column setup worked fine for another file, so I know I have the needed columns. I have removed all duplicates and that appeared to almost fix it. I've also tried the Notepad ++ Character Encoding trick, but that didn't work either.
I checked the various logs in var/log/ and didn't see anything of note.
Anyone know a good place I can post the file? It's slightly tweaked, I've scrubbed it of some data we can't share (without me getting fired).
Sorry, wish I could help. I am having the same issue. Even with just one product in my csv!
found the solution, added a column just after SKU named “store_view_code” (without quotes) and left the values blank.