Try pressing F4 key once just before saving the game on the memorycard and press F4 once again to toggle back the irq SIO to its previous state after you saved the game on the memorycard.
That procedure works with all my PS1 games: Granturismo1, Granturismo2, TOCA2,F1 97, and CMR2.
Please let us know if it worked for you
I hope this helps