Barcode reader (by 2 users)

I am having trouble with a barcode reader I purchased from Keenzo earlier last fall. It is not reading the whole barcode number, about one out of 7 or 8 scans. If the barcode number is 00014567, it might read 00000014 or 00000001 and sometimes it puts the letter J in there! It has done this on different types of barcodes, new ones, old ones, ones generated by different companies, etc. I have tried cleaning the glass, but that doesn't seem to help. Is there something I can do to it without sending it in? Is is still under warranty? MS330