The older versions may be used in some situations when the system is started with other than the default startup settings. Which versions are used in that situation depends on the configuration of your boot loader.
If your system is configured to use grub as boot loader, the configuration file /boot/grub/grub.conf will show you which kernels are still configured as bootable.
On many systems, /boot is a separate partition and freeing up space there may not create extra space in the other file systems. Sometimes /boot is also mounted as readonly and deleting the files is not possible in that case, unless the partition is remounted with read-write permissions.
Msg#: 4685474 posted 8:25 pm on Aug 2, 2014 (gmt 0)
Yes, your tmp and log files (especially error logs) fill up a lot of webdisk space! I'm glad you got that one sorted out. :)
Also, if you can access the package manager, either via UI or terminal, you can look up your list of installations and get rid of what you don't need anymore (especially outdated and no longer used libraries).