I had similar problems with DBRs happening every few days or so - not as severe as yours. The cause turned out to be my AV program was doing a real time scan of the DB every time Trainz opened (and presumably closed) it which may have caused corruption or was detected as "corruption" by Trainz. I added TRS19.exe and Patch Installer.exe to my AV exclusion list and (so far) the problem has not reappeared.
But it is possible that other factors may be at work in your case.