Q: Late2009 Macbook won't boot to Safe Mode

Using old 2009 Macbook with 10.6.8 OSX - VERY SLOW, repaired Disk Permissions frequently, usually takes about 1/2 hour to go through all the errors. Problem is I cannot boot to safe mode. Was only able to twice since I received the system brand new. Still have original discs but cannot use Time Machine for backing up files - WTH happened to Safe Mode??