The reason for the vague reply, is although both the products are 802.11g, there can be minor differences in the way manufacturers implement their versions, so sometimes different manufacturers products do not play well together.
If at all possible, try and stay with the same manufacturer throughout.
You say you have an unreliable connection, but do you know why? Remember, cordless telephones, microwave ovens and the like can influence wireless connections. Even something as simple as moving your router a few feet, could improve the situation drastically.