Image Resizer plugin error handling animated GIF?

Hi, I am using David Rencher’s Image Resizer plugin 2.1.2 for EE 1.6+.

I have discovered that the plugin can cause error resizing animated (and possibly other subtypes) of GIF. For them, EE gives PHP error:

Warning: imagecolorsforindex() [function.imagecolorsforindex]: Color index 255 out of range in /{my directory}/plugins/pi.imgsizer.php on line 5xx

Can someone please suggest a hack or fix to this? perhaps an option to turn off handling animated GIF or some weird color indexed GIF?