10.4.11 invisible files?

I'm working freelance on this OS and when I download a pic from the internet, the file doesn't appear in the folder on the server where I've saved it. I can however save it to the desktop. If I then try to drag it into my folder on the server, the msg tells me that the file is already there but invisible. I've asked the IT people to check my permissions, but want to know if there is a setting that should be changed on the computer itself. Will appreciate your input!

there are two apps that can do this easily:

search versiontracker (or google) for:
"mainmenu"
or
"onyx"

mainmenu is more user friendly and less likely to get you into trouble. onyx is very powerful and could get you into trouble if you go changing things willy nilly.
both are free.