In importing data directly from SFDC, I have found that 2 characters (ascii 129 and ascii 160) cause errors that are not easy to track back to the source data. ex.
Another row has already been processed with this key
I found a Billing City of "áSan Francisco" (but the first character looked like a blank in the SFDC UI). Removing the first character fixed the error that was being reported under Oakbrook Terrance. Here is what was inside the Billing City (second row is the ascii number) S a n F r a n c i s c o 160 83 97 110 32 70 114 97 110 99 105 115 99 111 Has anyone else run into particular characters that cause the import to fail?