This is likely a problem with source mapping. You should always map sources before uploading the transaction file - select Transactions=>Vendor Uploads=>Map Sources. Sometimes it's hard to know which source codes are being used by the vendor, as most vendors have multiple codes per source. You can look at the file - it's generally not difficult to work out which column(s) the sources are in, so you can see which codes the vendor is using, and make sure those are mapped correctly.