If you can get as far as a terminal, try executing the command to mount /proc from your login scripts. You need to know that the mount command works, and that procfs is compiled into the kernel.
The simplest explanation for this problem is that mount is being called as “mount” but it's containing directory isn't in your $PATH variable at that point in your start-up scripts. In which case, just give the full path to mount and it will be fine. Or, you can use something like:
Code:
export PATH=$PATH:/sbin/