Yes, I am getting ~1.2GHash/s according to my miner. I really don't know how much processing power would be required to do solo mining, and that is why I asked. Thank you for clarifying this. Therefore, I made the right decision to join a mining pool.

Now, will anyone help me with my real problem, the high number of rejected shares? I really don't want to waste electricity and the life of my GPUs on bitcoin mining if 40% of my shares get rejected.

Thank you in advance!