Forum Thumbnails not allways appearing
 

Since a server move, I've an intermittant fault on some of the VB sites hosted in it (but not all). Sometimes this error message appears when uploading images :

Quote:
Image resize failed due to your image library not having support for this image type

GD is present & I have recompiled apache to make sure.

When the error message does not appear then sometimes the thumbnail will appear in the post, other times not. I have done a clean re-upload of the VB files. I have tried with plugins disabled.

Any suggestions as what to check next would be appreciated !