SeekForwardOnly and AllowSearch are set to the same value, but they still do not throw exception for PNG and GIF images. It works fine for JPEG image.

Run the Sample Code. You will get a frame with 3 buttons.
Click LoadGIF button. If an image is loaded in the frame and if you don't see
any exception then the bug is reproduced for GIF.
Click LoadPNG button. If an image is loaded in the frame and if you don't see
any exception then the bug is reproduced for PNG.
Click LoadJPG button. If an image is loaded in the frame and if you don't see
any exception then the bug is reproduced for JPG.

If you see an exception saying that allowsearch and seekforwardonly can't be true, then it is working fine.

Source File: ImageInsert.java
Resource Files: Bird.gif, cup.png, flor2.jpg