I've been using two Vantec CB-IS100 IDE to Sata converters that mount on the rear of my ASUS DVD-E616A2 DVD-ROM and my ASUS CRW-5232AX CD-RW IDE drives for several years now with zero problems. I bought them from Amazon for around $15. USD each at the time. I see now that they're about $12. each.
These may cost a little more than your average eBay junk, but they are much higher quality with fully enclosed electronics and most importantly - they work, even with ATAPI (optical) drives! I've used them through three SATA motherboards and they're currently still working flawlessly on an all-SATA ASUS P6X58D Premium with Windows 7 64-bit and the same IDE optical drives.