Hello Udo,
In the mate in 3 position, Fidelity Electronics Chess Challenger 7 level 5 (24h average, level for mate in 3, eventually mate in 4, correspondance game) plays Qg6 in 8h 9mn 40secs, which is not the expected solution.
To be honnest, it was 1469 secs reported by Arena using the Messchess emulation 20 times accelerated
Cheers,
Eric