This should work:
Code
UPDATE `forums_USER_PROFILE` SET `USER_FLOOD_CONTROL_OVERRIDE` = '-1' WHERE `forums_USER_PROFILE`.`USER_FLOOD_CONTROL_OVERRIDE` = '';

All of mine are set to NULL though

I think you should just be able to:
Code
UPDATE `forums_USER_PROFILE` SET `USER_FLOOD_CONTROL_OVERRIDE` = '-1';

I am a Web Development Contractor, I do not work for UBBCentral. I have provided free User to User Support since the beginning of these support forums.
Do you need Forum Install or Upgrade Services?
Forums: A Gardeners Forum, Scouters World
UBB.threads: UBBWiki, UBB Styles, UBB.Sitemaps
Longtime Supporter & Resident Post-A-Holic
VNC Web Services: Code Modifications, Upgrades, Styling, Coding Services, Disaster Recovery, and more!