Just heard from a friend that his PD converter will not be covered under warranty because the serial number has been removed. Came from Ebay and apparently the same crook sells on Amazon. Mine is out of warranty so doesn't concern me and I have since bought a different brand but some might have recently bought one. Check and see if it has a serial number. PD has added this to their website. Hot PD Units
I also see WFCO had stopped their warranty coverage from Ebay vendors that don't have a service number to call, ie Ebay..Its on their website too. I don't know if they are stolen or not but thought if it seems too good to be true, it probably is.
As with a lot of resellers who are on places like Ebay or Amazon the low price is often deceptive. I bought a high end stereo receiver from Ebay, and when it failed about a year in found out the hard way there was no warranty coverage because the seller was not an authorized dealer. So it cost me another 150 dollars to get it fixed.
There is a lot of gray market material out there, not authorized to be sold in the US. This happens a lot with camera gear. It isn't illegal but the US distributor won't cover warranties. It isn't practical to send gear back to Hong Kong for service. B&H camera sells gray market camera gear but they tell you about it and cover the warranty themselves in their own service department.
Glendale Titanium 29E34TS fifth wheel
2012 Ford F-350 4WD Lariat 6.7L
PullRite OE Series Super5th 18K
There are a lot off crooks in Amazon's Marketplace. I will not buy from Marketplace vendors without carefully checking the vendor reviews. I actually read the reviews themselves instead of going by the ratings since there are so many people who do not know the difference between a vendor review and a product review. I look for clues such as consistent complaints of excessive delivery time, poor packaging, no or poor reponse to problems, wrong products being sent, etc. Another tip off is if a vendor sarcastically responds to poor reviews or consistently makes excuses. Amazon will not willingly stand behind their Marketplace vendors. I have had to hound them to get results. In one case, it took a BBB complaint to get them to respond (that did get swift results).
What's odd is Amazon will stand behind products that ship from their own warehouses. Problems are handled quickly and more than satisfactorily.