One of the big problems I find with OpenStreetMaps is the mapping of buildings. You can, for example, sometimes see the outline of a building with a number inside. When you place a pin there, you do not get the correct house number, but often a range of numbers. This is not at all helpful when you are looking for the specific building – unless you have put the correct address in a note.
Here is another good example. For Vienna there is a street market called Naschmarkt. You can find it in Pocket Earth as a street name. You will see, if you zoom in enough that the there are numbers which apparently relate to the stand numbers. If you look up and down the street, you will see that the numbers have four forms: only numbers, numbers beginning with A, with B and with C. The problem is: there are NO stands that begin with letters! You can see for yourself here: http://www.wienernaschmarkt.eu/staende.html
And it gets worse: if you put a pin in one of the stands (the grey areas are the stands), it does not show the number as displayed in the grey area, but instead, gives an address from the street next to the market!
My workaround is quite simple: let us (Pocket Earth users) edit the address as well as the name of the POI. Having a map giving incorrect information cannot be helpful.