Re: Airport Really Weak since Leopard upgrade
I too am having problems. I have updated three primarily wireless machines:
A year or so old MacBook, simple update, good signal strength, poor performance
A three year or so old iBook, simple update, good signal strength, poor performance
A 1 GHz TiBook (4/5 years old?), full clean install, very weak reception, lots of drops
All worked fine before the upgrade
Based on this, it seems that there is a clear correlation between Leopard on older machines and diminished wireless reception and between Leopard and reduced wireless performance.
I also found a maybe related issue by chance. In a web page for my ISP (Cox cable), they provide direct DNS addresses and suggest using these addresses to "Opt Out of Enhanced Error Results Page - Mac 10.5". After making this change (entering DNS addresses in Network Preferences Panel) I had no more problems with dropping/missing web sites. This did not affect wireless performance however.