When you use some kind of png fix in IE6 your google maps will not display a map but a grey area.
The markers are displayed as normal and so are the controls load fine.
Solution:
This is easy to fix: just clear the behaviour on your images inside the google maps element.
add this to your IE6 css [...]

If you ask someone to list web safe fonts you’ll probably get: Times New Roman, Arial, Georgia, Verdana, Trebuchet MS. We choose the fonts that are most likely to be installed on the user’s computer.
New computers (both mac and windows) have more fonts installed that we can use these days. What about Arial narrow, Arial [...]