Just wanted to try out some mining but when I press start on GUIMiner Slush Pool dosn't recognize it. Right now I can mine at around 60Mhash/s, is that too slow or is it any other problem?
When you mine with less than 1 GH/s (1000 MH/s) most bitcoin mining pools will show your hashrate as zero. This is likely to happen at many pools even with 10 GH/s. This is because the current default/minimum worker difficulty in pools makes you find proofs of work very rarely with a GPU. This again gives the pool very little data to estimate your realtime hashrate. If the pool has a hashrate display that covers more time (like average hashrate over the last hour) then you will probably see something.
Why are pools using such high worker difficulty? To function better with ASIC miners. Today 1000 GH/s is a slow miner and less than 1 GH/s is basically zero. There is a popular miner these days that runs at 13500 GH/s.
There are some pools that offer special mining servers for low hashrate miners. In that case the pool may be able to display a realtime hashrate. But the question is whether they show fractional GH/s or round off to the nearest GH/s.
You can mine without a realtime hashrate display on the pool's website. Mining still "works". Technically. The real problem is that you mine so slowly that you never earn more than some "bit dust".
The time for GPU mining is over: 60 Mhash/s don't even register anymore. We're approximately at 1.7 Ehash/s in the network today or about 3×1010 times your 60 MHash/s.
Check out In the ASIC-age, is it worth starting mining Bitcoin at home? for further elaboration.