My roots are Sarpy County, and I just sent a referral out for a listing that way 2 hours ago! I saw Papillion hit the top 10 list w/ CNN Money small town best places recent report. I told this to the Realtor I spoke w/ earlier today.
Anway........if you are asking Trulia to read an IDX feed from your site, it will not work. You can only grant permission to Trulia to crawl your site for data stored in your database on your server. An IDX feed is hosted on another server. Since you don't own that database, you don't have authority to grant Trulia the crawl. If you do not have data on your site on your server, Trulia isn't able to find any data in the crawl to upload.
You can try creating a feed. Google for xml conversion software, or try a local community college for a student who can write it for you. Once set up, it will automatically feed daily.