Hi you can try using the rules functionality combined with a Sunday calendar (even though you don't want to use a calendar) in the Month Days section. Create a calendar and add all Sunday days for each month and select it in the Calendar field of the job definition to use it. Next in the rules field of the job definition select the weeks you don't want to order using -Dn separated by commas and no spaces.
Result will order on 2nd and 4th Sunday of each Month. Effectively once every two weeks. I've used this functionality in version 7 just recently and I believe rules functionality was available back in v 6.2. Hope this helps with an alternate idea!
http://www.gssinfotech.com/services/inf ... rol-m.html