Is there any bug with Network Proxy of Ubuntu 11.10?

Recently I installed Ubuntu 11.10 Desktop on a system, and configured 'Network > Network Proxy' to use a proxy for Internet access. I selected ‘Apply System Wide'.

Unfortunately, I couldn't access the Internet through Firefox browser's default settings. I had to configure Firefox browser explicitly to access Internet through proxy.

Tip: for getting updates/upgrades behind proxy, read the blog: 'Ubuntu Linux: Update/Upgrade the Linux from behind an Internet proxy server'