In official Blender 2.71, by spliting a strip with a sequence of 722 images with Separate images function bpy.ops.sequencer.images_separate(length=x)
the .blend file jumps from 600 Kb to something near 132 Mb, without any packed file.
It seems a bit exagerated compared to the same steps done in 2.70a, where it increases from 570 kb to 4.4 Mb, much more reasonable.
System Information
Scientific Linux (CentOS like)
Linux lajeado 2.6.32-431.20.3.el6.x86_64 #1 SMP Thu Jun 19 14:01:59 CDT 2014 x86_64 x86_64 x86_64 GNU/Linux
Graphics card: 0f:00.0 VGA compatible controller: NVIDIA Corporation GT200GL [Quadro FX 3800] (rev a1)
Blender Version
Broken: 2.71 hash: 9337574
Worked: 2.70a
Short description of error
Exact steps for others to reproduce the error
Based on a (as simple as possible) attached .blend file with minimum amount of steps