I did consider the brochure was likely wrong, but web sites like Ivojo which advertise them also don't mention 576p or have the 'PAL progressive' flash on them.
Actually, after posting that I realised it was kind of moot anyway, my thoughts were that 576p would bypass the scaler but of course PAL is far less than 1024 horizontally so PAL would still need to be scaled I suppose.
It's definately PAL progressive compatible, I run our demo one at work off an Arcam DV88+ with no faults on PAL material. It shows up as 580p on the OSD though. It will also happily take 480/720p and 1080i material.