I just found out that my Sigma 17-70mm has the dreaded backfocus problem. I'm thinking of sending it to Gentec for repair. Unfortunately, the lens is purchased from ebay and hence I don't have the original receipt for it. There is a blank warranty card though.
So what are my options now? Do I have to eat the repair charge? Can I reason with them that since the lens has not even been released for more than a year yet, it should fall under warranty? Thanks for all suggestions and also please share any experience you have with Gentec.