iOS 5 OpenGLES error 0x0502

We just switch to the latest XCode and iOS version this week and are now getting errors when running our app on an iPhone 3GS (also with iOS 5 installed). There are no errors when running on an iPad 2 with iOS 5 installed.

We are using these build settings:
Target device: iPhone + iPad
Target platform: Universal armv6+armv7 (also tried with armv7 only but with same result)
Target resolution: Native
SDK version: iOS latest
Target iOS: 4.3

The following error gets printed to the console every frame after the scene has loaded:
OpenGLES error 0x0502 in /***xcode_porject***/Classes/iPhone_GlesSupport.cpp:172

The error code, INVALID_OPERATION = 0x0502, is very generic so it's hard to guess whats causing the error.

Some additional information from the console:

Renderer: PowerVR SGX 535
Vendor: Imagination Technologies
Version: OpenGL ES 2.0 IMGSGX535-63.14.2
GL_OES_depth_texture GL_OES_depth24 GL_OES_element_index_uint GL_OES_fbo_render_mipmap GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_rgb8_rgba8 GL_OES_standard_derivatives GL_OES_texture_float GL_OES_texture_half_float GL_OES_vertex_array_object GL_EXT_blend_minmax GL_EXT_debug_label GL_EXT_debug_marker GL_EXT_discard_framebuffer GL_EXT_read_format_bgra GL_EXT_separate_shader_objects GL_EXT_shader_texture_lod GL_EXT_texture_filter_anisotropic GL_APPLE_framebuffer_multisample GL_APPLE_rgb_422 GL_APPLE_texture_format_BGRA8888 GL_APPLE_texture_max_level GL_IMG_read_format GL_IMG_texture_compression_pvrtc
Creating OpenGLES2.0 graphics device

Has anyone else had this problem before? Is there a known solution? Does anyone have an idea of what may be causing the error to happen?

Thanks!

 

Thank you!