Hey guys, I'm wondering if anyone has seen anything like this, or has any tips to offer. I have a problem with my D70 (which is out of warranty) where, occasionally the mirror doesn't get completely out of the way of the shot. It swings up probably 80% of the way, leaving 20% of the sensor shrouded in darkness. When it does this, it makes a slightly louder "scraping" sound instead of the normal shutter/mirror slap sound. It seems to happen more often on longer exposures (maybe 1 out of 3 shots!). It only happens when a lens is attached to the camera. Here is an example of the resulting output: Here you can see that the lower 1/4 of the image is very underexposed. (The fireworks trails should start at the bottom of the shot, not part of the way up.) Any input would be appreciated!