Trulia isn't really doing an appraisal or comparative market analysis on your home. Several sites, including Zillow, use public records and a computerized program to come up with their estimated value. They are fun to look at ("gosh, my house went up in value by $200k last month!) but they are frequently very inaccurate. They don't take into consideration the interior, landscaping, updates, etc. Ad as you pointed out, they sometimes use distance, not town borders, for comps.
So their estimate of value won't affect a refinance or list price, if that's what's you want it for. You might get them to change it, but next month it will be different again. Not worth the effort, if you ask me.