[Biased turkey]

UncleClive is correct. Press F4 key just before loading or saving a game and press F4 again right after the loading or saving operation is confirmed.
Why it works, I don't know but hey who cares. Maybe one of the gurus could explain.
And you are right, that memory card problem is controller dependent: I had it while using a Micro$oft gamepadpro and it just disapeared the minute I switched to a Sony Dualshock + a PSX controller to USB adapter ( they are made by several manufacturers )

My $ 0.01625 ( CDN$ .02 )

 

[Biased turkey]

To Clumzy:
Hey, nice controller picture.
The adapter I got is the PSX/N64 to PC USB adaptor. See the following link:
http://www.levelsix.com/products/playstation/pcusbadapter.shtml

There is no shock option, but it's not important to me because I always turn the dualshock option off, specialy for the endurance races of GT1 and GT1.
I use a regular PS2 controller with it and it works great. The driver comes on a 3.5 "" diskette.
So, if dualshock effet is not important I recommend that adapter to you. Levelsix looks like a reliable company, I purchased twice from them and in both occasions received exactly what I ordered. The delivering time from the moment you order on line to the moment UPS rings at your door is 5 days.
Now if Dualshock is important to you, I remember that PSXEMU sells on line an adapter allowing the shock action. Maybe you should have a look at it.
I hope this helps.
I'm glad to help a " neighbour"