html help please

[netsavy006]

I don't know what's causing it but when I load a particular adspace on my page, it will show the 'advertise here' in white.

http://img137.imageshack.us/img137/8908/help1rq0.jpg

But when the page fully loads the 'advertise here' changes to a different font and color.

http://img137.imageshack.us/img137/5152/help2mb0.jpg

How do I go about preventing that from happening?

Thanks,
Andy...