Sprite Manager 2: 3GS & iOS 5-6 textures corrupt

Hi

I've been using SM2 now for over a year with my project. To date, my textures on all devices (4S, 4, 3G) have been perfect.

However, after upgrading to iOS 5 and over, the same textures show varying corruption on the 3G.

For instance, one one sprite, the silver outline of the button now has black through it. On another larger texture, a thick white line runs through it. I use a 'one size fits all' approach, making 1024 square atlases based on the 960x640 camera for the Retina display, with Pixel Perfect turned off and auto resize on (i.e. the "Size Sprite" option). In the past, the auto resize meant that the textures displayed correctly and perfectly on the 3G.

Brady, if you're out there, do you know what this may be? I'll try experimenting with different shader and compression options. Right now I'm using Sprite/Vertex Coloured Fast for the Shader, with RGBA Compressed PVRTC 4 bits format for the Atlases at "Best" Compression Quality.

Thanks for any help.