No such luck with the reboot of the children's computers. The key here is that it just randomly starts blocking any system with parental controls turned on even thought it is not set to block at that time (typically when I have 3-4 teenagers doing heavy on-line gaming). The only thing that fixes it is to disable parental controls (but that only temporarily solves the problem) or reboot the router.
Update: There was one thing unique in my configuration that shouldn't have caused the above problem that I changed back to the default. My router was set to 192.168.2.1 to support a configuration I had in the past. I moved the router over to the default 192.168.1.1 and now things are running well. This makes me think that Linksys needs to do a better job with QA/QC of their router code.