Very sneaky though, the minimum purchase price to get the discount is higher than the upgrade cost from CS5 to CS5.5, so you can only get the discount if you either buy the whole product or upgrade from an earlier version.
I was just about to buy it myself when I realised. Guess I’ll be waiting till I really need CS6.
Maybe the UK pricing is different or something because in the US store the minimum qualifying purchase is $375 and the upgrade from CS5-CS5.5 is $399 so it qualifies for the discount. I ordered mine yesterday and it worked out to about $360 (+ tax) with the 10% off. It seems like a good deal to me.
I doubt it’s an oversight. I was about to upgrade last time they had a similar offer, and I called them when the disount didn’t work. (It’s not immediately obvious on the website as you don’t get an error message if you apply the discount code, instead nothing happens).
The guy pretty much said the discount was intended for full product purchases.