YW glad u got it I know how frustrating mapping can be sometimes.
some advice when putting in tunnels, walls or fences use snap(upper left of med check snap box) and lower view to 1M for tunnels 4,8,16 or 32M for walls and fences.
when using snap and moving around map !!!DON'T!!! use arrow keys use CTRL and RIGHT CLICK to center on click.
using snap will put tunnels, fences or walls together fast and perfectly but you somewhat lose control of placing objects since u can only snap to a grid.
my advice is get used to using snap start with large 32M stone walls change view to 32M or 16M to snap walls at 90 degrees(make corners, square walls etc)
don't worry about not being able to put the set of walls exactly where u want them u can always move them once u get them linked.
this is a little advanced but once u get hang of snap u can do things like this
http://www.youtube.com/watch?v=XkwLcLOFVp8