DC:
 When I first read your post I was wondering if it was a "statue of limitations" question or the one you brought to light in your last post- if you have been made aware of a possible error on your part- it is in your best interest to report the possibility to your E&O carrier- this is not a question of " statue of limitations" but rather if your search is still the one that is on the hook for any errors-and as long as your search was used for the current owner for a purchase or a refinance with an owners policy- you remain on the hook until that person sells the property or re-finances (if there was no owners policy). An owners policy issued based on your search is good until that person sells the property and your liability continues until that same moment. The policy does not "expire" just because time has elapsed.
I hope that clears up some of your questions- but if you "think" you might  have a problem- please let the E&O carrier know- and it would be best to do so on the internet so you have the proof of doing so on paper and by e-mail, it just establishes the dates and times of your notice to them.
I have had the same experience myself and know the anxiety involved. It took my carrier 14 months to even acknowledge the facts, by then all the damage had been done.
Steve Meinecke
Franklin, Tn