A few questions from a newb

[DeadLader]

I'm relatively new to this all, and I have a few questions. I have a version 4 PS2, which I have modified with a ext. ModCube. I just went out and purchased a GameShark 2 to use as my bootdisc, but I can't seem to figure out which version it is. Also, whenever I attempt to load it up, If the modchip is on I get a screen that says playstation with gibberish below it, and if the chip is off I get the invalid disc screen. I know my chip is in and working properly because I have been able to play PSX copies on it properly.

SEcondly, regarding the PSX copies, a select few copies are coming up and attempting to display a screen stating that my console has been modified. I was under the impression that the PS2 modchips were able to get around this.

I apologize ahead of time if the answers to these questions are "common knowledge".