or just find / -iname thunder*; the dot doesn't have the significance it has in M$-DO$ and M$-window$
[what am I doing wrong?]
I wouldn't call it wrong, but at least sub-optimal (IMO): going to the site to dl it--I'd assume that your distro provides a package for it. Always, if your distro says `I can do this for you' [installing programs, fx.], just say `hey, great--thanks' and let it do it--it usually does it better than you or me. If you're crazy about compiling things yourself, then go for a source-based distro (I've heard good things about gentoo).
But hey, it might just be me that's spoiled by debian.