We had the same problem. Im going to guess its because your setting for icon size to show the pics is set very large. Its taking iPhoto so long to open because it has to go and create a large image for each of your 1400 pictures.
Next time you open iPhoto, be sure your icon setting is set to a small size before you quit.
In our circumstance we had to remove the entire photo library, boot up iPhoto, reset the slider, then replace the old photo library so iPhoto wouldnt take 10 minutes to load. once we reset the slider it only took about a minute. At the time we had an old G4 400mhz machine.
How old is your computer? how many mhz? This may also add to the problem by having an old slow machine.
If its only a minute to boot, thats not all that bad.