Aha, when I remove the chunk
	Code:
	00 00 00 09 76 70 41 67 00 00 00 64 00 00 00 64
00 87 26 5E E6
 from the file, it stops resizing it.  It did not do that when I removed the gama, srbg, chrm, phys chunks.  *plays some more*
the chunk is 9 bytes long, and its flag is [dec] 118 113 65 103.  I don't know what that is used for. . .
[edit-  Bam, I think I got it.  that chunk is "vPag", or virtual page which is something imagemagick (server image manipulation package) responds to.  The image you have dear has it set to [hex] 64, or a height/width of 100. ]