Hi, v5.2 is available (download link from my above mentioned webpage has been updated).
Fix for some engines when disable_ponder is set to yes, but the engine, despite having the option ponder valued to false, nevertheless plays using a command 'bestmove xxxx ponder yyyy' (and indeed did not ponder). It caused unexpected behavior from the GUI (at least using Arena).
Detected using an old Stockfish version (SF 9).
In such a situation, 'ponder yyyy' part of the message is now removed if present.

Sorry for any inconvenience.
Grüße,
Tibono