I have never used a Sparkle video graphics card, but have been using a lot of their stuff for about ten years. I wouldn't call them a subvendor. everything I have ever had from Sparkle, particularly power supplies, has been near perfection.
Something is wrong along the way. If you have time, drop an online notice to Sparkle as I know they wouldn't want to let this go by... and probably don't know about it. There is somebody between Sparkle and you that is allowing things to go bad.