My best guess is that there is something slightly off in the file, possibly a white-space character that you cannot see. Do you have an application (even a free one like Notepad++) that will let you view hidden characters?
I'd look for something like:
Extra commas in the data. Perhaps in a field that is supposed to be text delimited (e.g. "1,000.00" but is missing one of the double quotes)
Incorrect line breaks (e.g. most lines are CRLF, but some are just LF)
What would happen if you opened it in Excel and saved it as Tab delimited, just to test it?
Got it fixed! It seems there was something funky happening with my delimiter (a comma). I switched it to @, a character I knew wouldn't be in the data, and it all works now. Of course now I have to figure out how those extra commas crept into my data (which is probably an even bigger headache..) but at least I'm not pulling my hair out over what should be a simple import operation Thanks for the help!