When I double click on an entry in my Error List or Find Results list in VS2010, it docks the newly opened source code file not in the large window where all my other source fil
I was having the same issue but, for a number of reasons, didnt want to reset all my settings.
I draged all the open windows from the bottom panel area so they were floating, closed the find results window, redocked the error and output windows, then did a search (find in files) and the new floating window popped up, I then docked this to the same area that errors and output were in and when I double clicked on a file in the results window it opened in the right place.
I hope this works for you to and anyone else experiencing this issue...