First of all, sorry for bad English...
I got a Problem with the mirror modifier... The origin of my object is set to the 3D-curser, which is in the center (0, 0, 0). When I mirror my object, it duplicates to the other side (as it should) but the position is wrong... Why is that?... (The black line is the line I'm mirroring in)
When you see the objects from the top, It looks like the object is mirrored in a line that isn't even there, as you can see at the photo below, where the yellow line illustrates the unexisting line.
Any ideas what could cause this mistake?