New Alienware MX 14 teething issues

I am unsure whether this is pointless or not but I'll post anyway.

After much internal discussion with myself I bought an MX 14 and it suits me - I travel a lot and play games on the machine.  I have had Dell, Samsung and Asus laptops in the past.

The laptop seemed ok until I noticed some dust on the inside of the plastic cover on the screen.  Called Dell, took some photographs, engineer came out, took my 4 day old machine to pieces - opened box with screen in it and the replacement was the wrong colour.  I said to the guy to just unclip the covering and try to clean it which he tried his best but, hey, I don't live in an operating theatre....dust issues.  Anyway, I tried to live with the few specs...

I had the engineer out again tonight and he replaced the screen.  It's perfect now.  However, I have a horizontal line on the screen which is only visible when something moves through it - like when I fly through it in a game or when I watch a DVD or anything on IPlayer - it's really annoying me.

Now, I have updated the Bios and all the GPU drivers and the line is still there.  Has anyone else got this issue?  I spent a long time deciding on this laptop and whilst I cannot fault the support I could do without the hassle.  The engineer suggested he 'Might have to replace the motherboard" - not something I expected in all honesty and I am fast losing confidence in his this machine.

Also, when trying to type this my text is bouncing all over the page - is this normal?  18th November 2012 I received the machine and have had an engineer out twice, sent around 10 e mails chasing support and made 3 calls now in frustration.  If this is usual I am wondering whether I should just return it and get a refund.