Hi there, I've had some similar issues to what others are reporting here with my HTC Hero (stock android 1.5, European GSM version).
My phone would loose connection to the Wifi network pretty often and I would also have the "1 cm brower progress bar" issue where pages don't load at all in the browser.
I fiddled with my router (an ASUS WL-500Gp running OpenWrt) settings for a couple of days and finally found some settings that allows me to connect from anywhere in my apartment and I no longer have connectivity issues.
I wrote a small post on it on my personal blog with the technical details:
blog.jir.dk HTC Hero and Wifi Connectivity Issues