Maybe there is an issue for some. I look after a dozen or so Macs and have not experienced any issues.
It's a bug in safari 5. Sad.
I have had no issues with Safari 5, nor have I had any of these issues with my airport wireless connection either.
I have 3 Macs, 2 are absolutely fine, 1 has this issue.
Initially I thought I was being clobbered with WiFi interference, but now with some help from the linked threads, I've been able to at least have a working Safari on the Mac that has the issue. Not a great experience, but much better than previous.