Comment 7 for bug 34507

I cannot reproduce this problem on my system. I have tried by configuring gateway both in Routes tab as well as in Advanced Options of particular interface - in both cases gateway is properly written in /etc/network/interfaces and network works.
If you have used Routes tab, can you confirm that you had the right interface set on the right side?

Please report back if this is still reproducable with latest Dapper knetworkconf (3.5.2-0ubuntu6 or newer).