IE6 not always displaying pictures

[pogo]

I've got a problem where sometimes pictures on web pages do not display, instead there is a red cross in the top left where the picture should be.
I'm sure i've seen this problem before with solutions offered.
I'm using IE6 and the show pictures box is ticked in IE options.
Any help appreaciated.

[big man]

have you got a firewall running?? I have this problem occasionally with Norton. Turning it off works, but kinda defeats the object of having a firewall

[TITER]

if your useing a proxy server you can get this prob, look in tools/internet ops/conections/settings.
some add blockers use proxys