When i open a file it appears that my window is zoomed in extremely far because i can only see a few lines, if I make a selection window it finds points like there is something there but if I zoom out, in, or to fit i just get a glimps of my drawing for a few seconds then its gone again, and it will never show the whole thing.  Also my mouse is really slow and jerky while in the drawing view, if i move it up to the tool bars then its fine.......Anyone else having these issues or can give me advice to fix this????