On Windows 7 I am rendering a series of animations from Blender in a batch script that looks like this:

call "C:\Program Files\Blender Foundation\Blender\blender.exe" -b "E:\Project.blend" -S Scene1 -o "E:\exports\Fredericksburg1\Fredericksburg1_" -F JPEG -s 001 -e 435 -a
call "C:\Program Files\Blender Foundation\Blender\blender.exe" -b "E:\Project.blend" -S Scene2 -o "E:\exports\Fredericksburg2\Fredericksburg2_" -F JPEG -s 001 -e 480 -a
call "C:\Program Files\Blender Foundation\Blender\blender.exe" -b "E:\Project.blend" -S Scene3 -o "E:\exports\Fredericksburg3\Fredericksburg3_" -F JPEG -s 001 -e 180 -a

My problem is that after rendering one or two files, the rest of the Blender instances crash immediately after reading the preferences. The crash file just has this:

# Blender 2.69 (sub 0), Revision: 60995

It is not related to which project I use, usually only the first one or two render. I have tried a few things, making sure the computer didn't go to sleep or even the screen go blank, play around with the .bat file, but I haven't been able to get anything to consistently work. Any ideas?