When you download a link, it downloads the basic infomation first, then the graphics.
If the time limit for downloading the link expires (i.e. no data received for x seconds)then the link terminates, so a marker only but not the graphic.
Go to the control panel and open network connections, click to show on desktop when connected.This will put what looks like 2 TV's in your taskbar.
When you are downloading somthing. Right click and select Status, you can then see how fast (or if) you are receiving the signal.