Topic "Gaps in floor boards every 4'" a message from Dallendorfer

My flooring contractor has install a 2-1/4" solid wood floor over 3/4" T& G OSB. the floor trusses run side to side in the house. The sub floor is install front too back. The floor boards are install so they are perpendicular to the trusses which means the flooring is running the same direction as the long side of the sub floor. I have gaps in the flooring every 4' front to back. I am assuming these gaps are directly over the subfloor joints. Again, I am assuming as the sub floor shrunk form drying out over the past 5 months it created the condition I now have. Is this correct? should the flooring have been installed perpendicular to the long edge of the subfloor rather then to the floor trusses? How can this best be corrected? the gaps are less then 1/8".
Regards,
Eric