Maybe you'll have to post one of the images. You most likely may be experiencing problems when rotating your images. I believe the TFormFilter command helps in this area.
TFormFilter enable
Parameters
enable = 0 to turn off filtering; 1 to turn it on
Description
This command will enable or disable bi-linear filtering on images that are convoluted (altered) by commands like TFormImage and RotateImage.
This filtering allows the convoluted graphics to have smoother, more aliased edges. This also makes the operations slower. The bi-linear filtering can also create non-transparent edges what will mess with your transparency. Experiment for the best results.
Parameters
enable = 0 to turn off filtering; 1 to turn it on
Description
This command will enable or disable bi-linear filtering on images that are convoluted (altered) by commands like TFormImage and RotateImage.
This filtering allows the convoluted graphics to have smoother, more aliased edges. This also makes the operations slower. The bi-linear filtering can also create non-transparent edges what will mess with your transparency. Experiment for the best results.