Ijaz:

I have the same problem, here is my solution:
find a posting in the main list where the "last post" show some time just before you left the previous location. Read (click on the last entry) that post, click back, click "referesh" and voila! the flags show what you have not read. The only problem with this method is that when you enter a post some posting you have read at the previous location will still be blue.

Anyhow, Craig is aware that some of us work at multipl;e locations and is looking into "server stored cookies" which will be the absolutotally perfect solution to this.

Have fun,

Erik