We had 6.5.1 set to 3 years as the default as well and did not run into this issue...
I came from Classic 6.7.2 and it searched since Day 1 without a problem. I was actually looking for a "search all" option, so I wouldn't have to change the "year" value every year.
Rick - Just out of curiosity, tho... and assuming the server could handle it... My BB has been live for just over 5 years. What would happen if I set the search range above that, say to 10 or 20 or even 1000 years? Would it break, or work as "all time"?