I have a new account now to buy stuff, it works fine on my main console. When I try to open the account on the other PS3, it says "follow the instructions in the email message to reset the password using a PC". Why is that? I tried changing it, but even then it still says the same thing. How I can use my account on the other PS3?

You can, I am %99 sure. The limit was 5, then restricted to 2. My old accounts are on different consoles (Although I didn't try to open them recently, they are there).

BTW, I know how to deactivate an account for a particular console, but the limit being 2 tells me that its not necessary. I use both of the consoles  so I need access on both of them. If I am wrong this is not nice.

You can log into other ps3s my friends have done so. Just create a new user then follow steps and proceed to log in with your username/password.

weird....my account is on 3 PS3 and 2 PSP. And I dont have any problem :(

When having your account in multiple locations, make sure both aren't trying to sign in at the same time.

I am doing the same thing but everytime it sends me a mail to change the password and does not let me log in.

Maybe Ajescent is  closer, I was trying right after logging out on one PS3, so the time was very little in between. I'll try to do it after giving it some more time.

that problem just happens in the same PS3???

After the PSN Hack, I had to do that with all of my accounts on my PS3. Not sure this is relevant, though. Good luck.

Ypu can have yor PSN Account on how many PS3 you want... the issue is when you want to download... only two PS3 are permited right now.. and You will have to deactivate one to use other..

No. I can log in with that account on my main PS3 just fine. The other PS3 does not let me log in.  I tried the old accounts and they work, I don't know what is wrong with this.