You shouldn't be rebuilding the log - you're going to cause corruption and data loss that way. See Corruption: Last resorts that people try first....

It's likely that something in the h/w setup in each location is causing corruption. Gail - it's pretty hard to cause a suspect database by messing with the system tables.

You need to put the suspect databases into emergency mode and run DBCC CHECKDB on them to find out the corruption.

Do you have backups? Rebuilding the log is a horrible solution to dealing with corruption.