Mouse down offset

I compiled and ran testbitmap.c in sdl 1.3
I noticed that the location of the bitmap is consistently quite far away
from where the mouse is clicked.
I logged the x and y in the dst used by BlitSurface and it seemed to be
rather sporadic but looked like a function of where I first click on the
screen. If I click first at the top left of the viewable area, then the
offset is only about 150px for x and y. Wheras if I click towards the bottom
right, it’s much higher.

I’m running MinGW (GCC 3.4.5. ) compiled from MSYS. I configged and
installed SDL from svn rev 4225.