Did you see a bad flash? The settings in the bios itself may need a change or two to correct a good flash. A reflash with the same 1901 version may see that corrected if something didn't program fully. Generally the newer version has fixes for correcting problems seen in the earlier versions. Usually you can't go backwards on flashing unless you can find a tool for clearing all programming off of the eprom.
You can also order a new eprom with the version you want preflashed direct from the board manufacturer at times. But that's the $25 + S&H costs and special DIP tool needed for insertion needed as well. What type of problems are you seeing on that model board? That will be a big help in advising other steps to look into.