Actually there are two for Photoshop CS5: CS5, and CS5 extended. There is a large price difference between them. Obviously if you try to upgrade to CS5 Extended on the basis of CS4 standard, you will have a problem unless you pay them more money. I don't how this is designed to confuse and annoy people. But Bart's basic point is well taken. The upgrade path should be consistent.
Hi Mark,
When I purchased my upgrade (soon after it became available), I spent half an hour on the phone with one of the largest serious software sellers in my country, as we were trying to figure out which product code was appropriate for my upgrade path (all were English versions, the UK one), and that was for Photoshop alone. Upgrades from older versions (more expensive), upgrades from more recent versions, upgrades from regular to extended, all with abreviated product descriptions which were clear as mud (taken directly from the Adobe product descriptions).
I managed to get the correct Photoshop CS5 version, and apparently Dave is also up and running, so all is well (although I believe there is a bug in the HDR pro conversion to LDR, and artifacts).
Cheers,
Bart