Dividends are generally not a huge issue in connection with the negotiation of VC term sheets; however, founders need to watch-out for mandatory cumulative dividends, as well as stock dividends that could be extremely dilutive to them.
Not all «preferred shares» have the right to receive cumulative dividends. Some cumulative preferred shares carry limitations. For example, the company may only have to pay cumulative dividends if it liquidates. In addition, paying out cumulative dividends doesn’t take preference over paying the company’s creditors.