Win7 64 bit, 16 igs RAM, an AMD 7xxx GPU, third gen i7 processor
Broken: hash 5693337
Short description of error
In certain cases, subdividing two edges at once can create an invalid face, even though they are cleanly separated and are attached to valid geometry. That case appears to be when there's an Ngon and both edges border it.
Exact steps for others to reproduce the error
Open the .blend file and subdivide what is selected