Why can't I check my Gmail on my PSP? I put in my password and name then I click sign in then is says this page is invalid.

That happens to me and I could not find the answer

You can't check gmail on your psp because it is a java based interface and the psp does not have the new version of java... if you want to check your gmail on your psp you have 2 options..
(1) hack your psp-downgrade to version 3.5 and find an app that you can use. Copy and paste the app into your game folder then open it... however you will probably want to be careful, you might brick you psp, not to mention, no offense, but you guys seem like psp noobs so I would NOT recommend it unless you know what you are doing. (personally I have not done it because I am to afraid that I will brick mine, but I do know that it is possible. Just read up on it... that's what Google is for :)
Or... (2) go to m.gmail.com however this attempt does not work for me either. It is suppose to because it is a mobile client of gmail. I have heard that other people can get onto it just fine.
Also if you want to use gmail IM or any IM for that matter you can go to m.ebuddy.com..
If anyone else knows how to get gmail on psp or if there is any version 6.20 hacks or apps out please let me know.
Thanks,
Joey