Hi Geoff,
This is normal behavior, not a bug. The selected pixel rejection algorithm has nothing to do with the state of the clip low range and clip high range parameters. In other words, ImageIntegration implements two different types of pixel rejection: statistical rejection (sigma clipping, linear fit clipping, etc) and range rejection. The former uses adaptive methods (with the sole exception of min/max clipping) based on robust statistical analysis, while the latter performs an unconditional rejection of all pixels outside a prescribed range.
If you want to perform no pixel rejection at all, you have to select no rejection for the rejection algorithm parameter and disable the clip low range and clip high range parameters.
