Problem with dock, right click and drag and drop.

Hi everyone. First of all, thank you for all the support I got there. Really appreciated.

Last week, I started to have problem with my iMac 21,5 inch (2011) and I can't find any solution. I saw online that many customer had the same problem and the only solution was "restart your computer or log out off your session".

1 - When I restart the computer, everything is going fine but after 5-10 minutes, I am starting to get problem. It is not possible to do a right click (anywhere, on any application). Also when I put my mouse over an icon it should be highlighted but it won't (menu, dock, drop down menu etc).

2 - The magnification on my dock will also stop working after 5-10 minutes. The magnification will work when I put my mouse over the first icon but if I move over the other one, the first one will stay "highlighted". It is also not possible to do any right click on it.

3 - I can't drag and drop anything. If I try to drag something over my desktop for example, the icon will stick to the pointer and won't move from there. I need to fight against my keyboard and the mouse to get rid of it.

Here is what I did:

- Searched for any bluetooth device = Nothing excepted the keyboard and the mouse (apple stuff)

- Disconneted the trackpad and removed the barries (it could be because of it)

- Removed the keyboard and the mouse - Tried two different one (Wired)

- Tried to remove some files on the Preferences folder

- I ran ONYX to clean up everything

- I did a disk repair with Disk Utility

- I did a format / clean install of Snow Leopard throught the installation CD

- I did a format / clean install of LION (my friend borrowed me one so I can see if there was a fix for it) - I will install my version back, don't worry

I use this computer for photo editing, photoshop, music editing....so I can't use my computer at all with these problem.

Anyone have a solution? I can't find anything else over the internet. I don't wanna throw it through the window so please help. That would be much appreciated.

Right now I am running without any application. Everything is unplugged. I am using a wired mouse / keyboard.