I'm hitting something similar presumably with the same cause. The blender snow with ~900 images seems to do the trick. I get the traceback when trying to open the animated titles menu again.
Traceback (most recent call last):
File "/usr/lib/pymodules/python2.6/openshot/windows/MainGTK.py", line 1659, in on_mnu3dTitle_activate
File "/usr/lib/pymodules/python2.6/openshot/windows/BlenderGenerator.py", line 34, in __init__
File "/usr/lib/pymodules/python2.6/openshot/windows/SimpleGtkBuilderApp.py", line 32, in __init__
glib.GError: Failed to open file '/usr/lib/pymodules/python2.6/openshot/windows/ui/BlenderGenerator.ui': Too many open files
Ubuntu 10.10 AMD64 OpenShot 1.3.0 from PPA.