Does anyone grow Lithodora?

I would love to be able to grow lithodora (Lithodora diffusa) in my garden. Three or four years ago, I came across Lithodora for the first time in one of the big box stores, and its bright blue flowers called out to me. It is a low-growing groundcover with a growth habit similar to creeping phlox (Phlox subulata) or candtuft (Iberis sempervirens). I was not familiar with the plant, and neither was anyone in the garden center, but after reading the plant label, I decided to give it a try.

The plant I bought looked healthy and was loaded with buds. I planted in a partly sunny area and was careful to make sure it was well-watered as the heat set in. It quickly deteriorated and was dead by mid-summer. 

The next year, I was again lured in by the bright blooms in the spring, so I decided to try it again. This time I planted in a different area and gave it less water. Same result.

I decided that it was one of those plants that really wasn't suitable for our area and initially resisted when I saw it in the garden center this spring. But then I found a large group of it on the clearance rack and the plants looked completely healthy. So I decided to try again, this time planting in an area with excellent drainage but keeping it well-watered. It lasted long enough to get my hopes up, but by the end of summer, dead again.

So if there is anyone out there who has had success with lithodora, please share your secret. How much sun does it get and is it morning or afternoon sun? What is the soil like and does it tend to be moist or dry? Do you speak to it with encouragement or threats? (Just kidding about that last one, unless threats are working for you.)