wall connections

[RobJ]

I am trying to split a standard room shape into two by dropping a wall across the middle. However, the additional wall does not connect to the room walls, but leaves a small gap at either end (or occasionally only one). I have tried putting connection points onto the edge walls I want to connect to, with no change, I have tried setting the dividing wall length but it is automatically shortened. I have looked and AutoConnect is selected in options. I am using Visio 2010 Professional in a Windows 7 system, the program was downloaded less than a week ago so I haven't had time to fiddle with any settings that might get unusual results! I need to use 'Space autofill' to find the area of one half of the room but the space fills the whole room by going round the dividing wall. I know that there are various ways I can bypass this problem (replace the single room with two, manually fill with spaces and then use union etc.), but I just want the program to do what it says on the tin!