5.52 is a direct downgrade from A6.
This means it's basically A6 but with several features removed (like the A6 mode which supports hardware T&L).
this is why it shows the A6 logo and newer DLLs MAY still work (not all DLLs WILL work, though).

However officially it is A5. I guess someone forgot to update some version numbers and icons.
When you run a game it says 5.52.