I had that problem too but it was fixed with 10.5.1. For me it was anyway.i switched back to tiger on my macbook because leopard's wifi was unstable and kept disconnecting...
Leopard there is absolutely no reason to run Tiger over Leopard. The interface sucks, it's old, and the new features of Leopard are far better then those of Tiger. There are a few issues with Leopard; hopefully, those get fixed soon.
im still using tiger, but thats only because ive tried to upgrade to leopard 5 times.. all unsuccessfully ..
i get to a certain point where it says my system cant be upgraded because it isnt 10.4
when my computer (aluminum iMac) is 10.4.11
so frustrating