Litecoin solo mining problems (what the hell, 1,5GH/s with hd4770?)

[mq1]

I am posting here because i am a newbie in problems. I followed instructions shown in this (https://bitcointalk.org/index.php?topic=83371.0) topic, and everything seems to be working.

besides.. the Reaper miner shows that i am mining on ridiculously great speed: 1,5GH/s only by using my old HD4770 gpu. That isn't ture, is it? And like you can see from the picture, it doesn't show any speed in the "kH/s" section. What's wrong? Where do i see the real mining speed?

Also: do i need to press "start mining" from the limecoin client too?

I am only mining with my GPU.

pic: http://picturepush.com/public/12557704

What do you think?

Ps. I am very thankful for the writer of the tutorial as it have helped me a lot.