[q]Originally posted by: Iain71
Cheers guys - I don't know what the original files were - but its all sorted
now. Apparently whatever caused them to act up happened when my client cropped
the originals.[/q]
*blinks*

The files were BITMAPS. The old-fashioned, uncompressed, Windows-standard .bmp
file. Two people, using independent means have verified that this is so. When
your client cropped them, he must have not saved the file properly. Unless your
client knows how to use an imaging program properly, the same problem is going
to happen again. He or she cannot simply add a .jpg extension or change the
extension to .jpg and call it good. The extension must align with the file's
header information, which are the first few bits or bytes in the file before
the actual image data.