crash in presentRenderbuffer:GL_RENDERBUFFER and/or GLES2VBVO::EnsureVerticesInited

I am experiencing two random crashes, but they only seem to be occurring on the iPhone 4. All of our Android devices and any Apple device newer than an iPhone 4 does not crash. We recently started building for iOS, and have had working Android builds for over a year.

The iPhone 4 is on iOS 7.1.2 Unity is 4.5.5.f1 Xcode is 5.1.1

The phone was on iOS 7.0, and upgrading to 7.1 did not help. We also tried a build with Unity 4.5.5p5 and the issue still persists.

One of the crashes is in DisplayManager.mm:

[surface.context presentRenderbuffer:GL_RENDERBUFFER];

The other is in the OpenGL library at:

GLES2VBO::EnsureVerticesInited(bool)