I've had this issue since day 1 of owning P3Dv4. Is this an issue with P3Dv4 itself (as a software) or could this be some sort of incompatibility? I'm surprised I haven't seen more posts on this issue, however it would make since if it's only an issue on my end.. The Blendmask is an 8bit grayscale (uncompressed) Tiff - The same format I have been using from FSX to P3Dv3 without issue. Any ideas?