Vizio checkered display problem and lagged mouse

[DRJ1014]

So my parents just gave me a 37 inch LCD HDTV 1080p 50,000:1 120hz.

I went down to best buy and was talking with one of the guys there on which cable would be best to set the tv up to my computer with to be used as a monitor. He pointed me in the direction of "Dynex DVI-D to HDMI" so i purchased it got it home plugged it in and got a picture.

Now for the problems...

Right now on websites/documents/aim conversations etc I have like tiny checkered lines.

problem 2... not sure how to explain it (currently brain dead from being sick) but the lines on Hardforums where "Tags, Post Icons" are and around the message box have like a static? look to them.

problem 3... my mouse and keyboard has about a .5 sec lag to it.

im running a ATI Radeon HD 4350. Have the logitech mx 5000 bluetooth keyboard.mouse

I am runnning the recommended resolution at 1920/1080

 

[DRJ1014]

Could it just be the cable? Should I go back and find a DVI-D to VGA?

 

[DRJ1014]

So I went back to Bestbuy and just got a vga to vga cable. That fixed the 'checkered' look but I still have the lag to my mouse and keyboard. Also the static(?) kinda look on the white part of the lines around hardforums "Options message etc"box is still there.