The profits have to be shared among all the partners.
You do not have as much control over the business as there are a number of owners. All of the partners will want to have a say in important decisions and this may lead to you being overruled.
Deeds of partnership have to be rewritten if a partner leaves or dies, which can take a lot of time and cost money.
There can be disagreements between the partners. This can cause major difficulties as partners are bound by any commitments made by a single partner, even if they did not agree to it.
The partners have unlimited liability so they could lose all of their personal possessions if the business goes bankrupt (this is not true for sleeping partners as they have limited liability).