I am sorry people are having trouble with forks...this can happen with low hash rate. If it keeps happening I would advise you mine on a pool. Sorry, I've not done anything on purpose to make you lose coins!
You mean low total hashrate of the network? Because I had 5Mhash thrown at it and I don't think the wallet/nodes could cope because it seemed to get backed up when finding too many blocks. They all got verified and approved though, so there's something else that went wrong along the way that took verified coin in my wallet and stopped recognizing it on the network a short time later.