Default Data, log and backup location changed after reboot

Has anyone ever seen this or know why this would happen? I have a 5 year old windows 2003 cluster running a named instance of SQL Server 2005 enterprise. During the install of SQL the log and data files were created on the H drive. (Making H:\\MSSQL.1\\MSSQL\\Data the default for both data and logs and H:\\MSSQL.1\\MSSQL\\Backup the default location for backups) After the install we run a script to update the Reg to change the default locations as following: Data = E:\\MSSQL.1\\MSSQL\\Data LOG = F:\\MSSQL.1\\MSSQL\\Data Backup = G:\\MSSQL.1\\MSSQL\\Backup Script

--Set backup loaction in the registry  
exec master.dbo.xp_instance_regread N'HKEY_LOCAL_MACHINE', N'Software\\Microsoft\\MSSQLServer\\MSSQLServer', N'BackupDirectory', 'REG_SZ', 'G:\\MSSQL.1\\MSSG\\Backup'    
--Set data loaction in the registry  
exec master.dbo.xp_instance_regwrite N'HKEY_LOCAL_MACHINE', N'Software\\Microsoft\\MSSQLServer\\MSSQLServer', N'DefaultData', 'REG_SZ', 'E:\\MSSQL.1\\MSSG\\Data'  
--Set log loaction in the registry  
exec master.dbo.xp_instance_regwrite N'HKEY_LOCAL_MACHINE', N'Software\\Microsoft\\MSSQLServer\\MSSQLServer', N'DefaultLog', 'REG_SZ', 'F:\\MSSQL.1\\MSSG\\Data' 

Now last week the OS on the servers in the cluster were patched and after the reboot all of the default locations where changed back to: Data = H:\\MSSQL.1\\MSSQL\\Data LOG = H:\\MSSQL.1\\MSSQL\\Data Backup = H:\\MSSQL.1\\MSSQL\\Backup These servers have been patch several times throughout the years and this is the first time it has ever happened. We have seen it switch Server Authentication a few times from Mixed to Windows.