Tested Build : build 1.6.0-b66 and pit build
Build Location : /net/sqesvr-nfs.sfbay/global/nfs/deployment5/pit_builds

Build Location : /net/koori/onestop/jdk/1.6.0/latest
OS/Machines : DNM-011(winxp professional), windows-64(winxp professional), JITENDER(winxp home), paris2(Linux ADS3.0), jd-sqe01(linux ADS4.0), kgb(solaris10)

Problem description:
"select(uri)" method of "java.net.ProxySelector" and com.sun.java.browser.net.ProxyService API is behaving differently on different browsers, with internet connections settings set to "Use automatic configuration script". With automatic configuration script containing three proxy enteries, this API will return list of 3 enteries when called inside the IE browser(which is correct behavior) while on firefox/mozilla the list always contains 1 entry. For example if autoscript contains information like scaweb1.sfbay, scaweb2.sfbay and webcache.sfbay then inside IE it will return information about all the three proxy servers but inside firefox/mozilla it will return information about the very first proxy(scaweb1 in this case) ignoring the information about the rest of the proxy servers listed inside the script.

Steps to reporduce:
1) Install JRE from the above mentioned locations
2) On unix make sure that you register your browser with this newly installed JRE
4)Create .java.polcy file inside the <user_home> with following permission:
 java.net.NetPermission "getProxySelector";
5) Change the browser connections settings by setting "automatic configuration script" to following URL
http://sqeweb.sfbay.sun.com/deployment2/jitu/plug-bug/proxy_detect/proxy.pac
(Simple script which returns info about 3 proxy servers)
6) Load the following applet inside the different browsers
http://sqeweb.sfbay.sun.com/deployment2/jitu/plug-bug/proxy_detect/proxy_detect.html
Check Java Console
On IE( correct behavior)
ProxyTest AppletStarted...
No. of elements in proxy list: 3
proxy at index[0] HTTP @ scaweb1.sfbay.sun.com/129.145.155.90:8080
proxy at index[1] HTTP @ scaweb2.sfbay.sun.com/129.145.155.40:8080
proxy at index[2] HTTP @ webcache.sfbay.sun.com/129.149.246.4:8080

Mozilla/FireFox(Incorrect)
ProxyTest AppletStarted...
No. of elements in proxy list: 1
proxy at index[0] HTTP @ scaweb1.sfbay.sun.com/129.145.155.90:8080

If you are able to see the output as above with mozilla/firefox then the bug is reproduced

You can try loading the following applet using com.sun.java.browser.net.ProxyService to reproduce the problem
http://sqeweb.sfbay.sun.com/deployment2/jitu/plug-bug/proxy_detect/plugin_api/proxy_detect.html