Crankin, I honestly don't know what your personal issues are, but I can tell you that balance on a bike is critical, and the frame geometry can have a large impact on that.

Another example is how much of the riders weight is on the front vs rear of the bike (as Lisa pointed out). For example I ride a smaller framed bike than my height would predict, cuz I have long femurs so need the seat to be very far back (and need a very slack seat tube angle, <73) but then to feel balanced on the bike, I need a very short top tube (48-49cm!) which means a 24" front wheel to get a bike without TCO and with decent handling (i.e. I have a classic terry body).

My point is the original poster needs to consider all these things.