Inspiron N5050 touchpad not working properly when connected to AC adapter

Hi,

I have just bought my Inspiron N5050. I connected it to the AC adapter and followed all instruction of first use and then have noticed that the cursor barely move. At the beginning I thought it is probably wrong setting of the touchpad, but it wasn't. I got really fed up to do anything on this laptop and turned this off. After a while I turned it on again without the adapter and it worked properly. I was happy that the problem was solved. But not for long. As soon as I plugged the AC adapter on, the cursor was jumping, moving slowly or not moving at all, scrolling pages etc. 

I have read few posts already about this issue and came to the point that I need to update my BIOS or touchpad driver.

Can anyone please instruct me on this which version I should use - I came across these 2 drivers and dont know which one to choose:

 http://www.dell.com/support/drivers/us/en/19/DriverDetails/Product/inspiron-15-intel-n5050?driverId=GMDG1&osCode=W764&fileId=3002061375 or

http://www.dell.com/support/drivers/us/en/19/DriverDetails/Product/inspiron-15-intel-n5050?driverId=R317839&osCode=W764&fileId=2731121867

The first one looks like it is the most recent, but is it the right one?

Also the touchpad - is this the right one - http://www.dell.com/support/drivers/us/en/19/DriverDetails/Product/inspiron-15-intel-n5050?driverId=H6CXN&osCode=W764&fileId=2731102116 ?

What if the fault is in the adapter and not my laptop/touchpad? Shouldnt my laptop be up to date if I bought it only this week?

I am looking froward to hear from you on the solution to my problem.

Thanks and regards,

Zania