A decreasing dividend could indicate a simple cash flow issue that needs to be corrected by pulling back dividend payments. Another issue could be sales have declined and there is not enough excess cash to pay toward investors. Again, if the dividend amount begins to fall, you should take a good look at the fundamental data and understand what their reasoning is. Not every time will it be something bad, but it certainly is worth your concern for the short term.
When looking to invest in companies, and item you should be looking for is dividends. A dividend is simply money returned to shareholders and is usually paid when the company is performing well. Not all companies give dividends, but it certainly is a welcomed addition many investor seek. Specifically, you want to look at the last dividend paid and determine if it is inline with previous payments are has changed either up or down. Typically, you want to see dividends remain constant or increase. If a dividend begins to decrease, this could signal the company needs the extra cash to go elsewhere.