I have a shed which houses my AP which runs an Omni monopole (about 6-8dBi)on a bamboo stick 1.5 metres above my shed roof. I use a directional antenna connected to my laptop card and have no probs. I have also used a cantenna in the same position aimed at my house with good results using only my laptop card. You also might need to take into account that your house may be blocking the signal, especially if it was built 20 years or more ago. They used aluminium sisalation then rather than the tyvek-type paper used these days. I agree with etienne try and network the card and the AP in close proximity to rule out software probs. check to see if u are setup as ADHOC or INFRASTRUCTURE.