Either not a lot of people still play their original Playstations (lol), or few people have this problem, but my controllers don't work when a memory card is plugged in. They work fine otherwise. I've tried another controller port, but it makes no difference. Two different controllers, and two different memory cards.
I'm afraid if I buy another console, I'll have similar or worse problems.

Does anybody know how to fix it?
(I would play on PS3, but it freezes up somethin' awful while playing older games)

That's a fairly common problem. The slots are really close together. If you know someone who is handy with electronics, they may be able to re-solder the loose connector inside the machine.

I think the last model PSX, the small white one is more reliable. If you choose to buy another machine.

My boyfriend has been poking around at it for a while now, but he can't figure it out. Can you be a little more specific as to which connector? I know absolutely nothing about electronics and he knows nothing about game systems. (But he has other electronics knowledge.)

I'm sorry, Lisa. I just haven't been able to find the solution anywhere else.

I think it's your controller port, since that's what stops working. HERE is a place that sells the replacement part.

I have already bought a new controller port, and it doesn't fix my issue. It still occurs. *sigh*

Rats, then it might be a problem with the board itself. Sorry, these machines weren't made very well.

Ah, well, thanks for trying to help.

Is the MMR contest still ongoing?

Yep! I'm ending it on September 1.

I got a white one, and it works! Started a new MR2 save last night, trying to teach my boyfriend. (He's only ever played Atari games before. O_o)

That's awesome! Finally found a working MR2 copy,
unlocking monsters I've never gotten before, feels
so good

Yay!

I've had similar problems, but I have three spare
PSXs, and when my main one breaks down, I find the
broken part and switch it out. I've been using the
same PlayStation for almost 16 years now.