(no subject)

I hope someone has an answer to this:

I am occasionally running into situations where bg gifs don't tile 
together well... in other words, there are gaps between them. Sometimes 
the gaps are clearly empty channels, other times, they look like 
differently colored mortar between bricks. This only happens on certain 
gifs. Why?

See:

http://www.cts.com/browse/jsent/travel.html for an example.

Thank you,

John Salerno