I'm having the same problem. My son, who is computer savvy, doesn't really know what's happening either. I'm using 10.3.9 too. I'm having some luck with Sea Monkey (at least I can read my emails now).
Macintosh Requirements
Any Mac running Mac OS X Leopard 10.5.7 or Mac OS X Tiger 10.4.11 and Security Update 2009-002
Mac with an Intel processor or a Power PC G5, G4, or G3 processor and built-in FireWire®
256MB of RAM
Top Sites and Cover Flow on Mac OS X Tiger require a Quartz-Extreme compatible video card.