Apache returns truncated image

I am bringing up an image directly through firefox (no PHP or other scripting code) and it appears that Apache is returning either a truncated image or a corrupted image.

I get the top 5-10% of the image. It appears that I get complete width and height info.

If I hit "refresh" (in firefox) I get about 5 more lines of the image. And if I hit refresh again I get another 5 lines.

In IE I get the same initial 5-10% of the top of the file. But refresh does not give me any more.

Bringing the image up across the network through a mapped-drive reveals the entire image. (so the image(s) itself seems to be okay).

(If I point firefox to the image via mapped-drive rather than through Apache firefox brings the image up just fine. So it does seem to be Apache at issue)

Any ideas?

From serverfault ChronoFish

• What operating system is this on ? Is the file you are serving local to the server apache runs on, or is it also accessed over the network ?

  You could try the following directives in your Apache httpd configuration file to see whether it is due to problems using the sendfile-systemcall or MMAPing :

  EnableSendfile Off
  EnableMMAP Off

  (http://httpd.apache.org/docs/2.2/mod/core.html has more information on those)

  I have seen those two be the culprits before, though only if there was something funky going on with the storage subsystem. It is usually a bad idea to disable these, since it eats into performance.

  From eike