Back in school, I ventured into a cyber cafe business with a colleague, it was more like a printing press, and since it was in a school environment, we had a lot of customers. She rented the space and got a printer, i got few laptops and focused on just typing and printing. Even when our clients came to me as the perceived boss, I always made sure to refer to her as the boss, she did not want a share in my profits because we really grew to understand ourselves. I think that was my best partnership experience ever.
People enter into partnership for different reasons, which could be lack of money to establish a sole business, desire to share resources, desire to learn from a more skilled person, etc. Challenges are bound to occur in partnership because of individual differences, it is difficult to find one who would completely agree with you on something. Possible reasons for drifts in partnership include misunderstanding, greed and desire to dominate.
Misunderstanding is a common problem, like I stated, it should be expected of another to completely understand and accept your views, we are different people from different backgrounds and have different mindsets.
Greed is another problem faced in partnership, when one partner becomes discontent with the share of profits or is not comfortable with the share of resources, problem sets in.
The desire to dominate tends to be in every human. So when one partners feels it is he or she who is supposed to be the one to call the shots, that's a problem.