error on LILO after RH 7.1 up2date

I just ran up2date on my 7.1 box and elected to only update the kernel and
xinet.  The Kernel went from 2.4.18.X to 2.4.20.X.  I received an error at
the finish,  "LILO test failed"  this is not an exact quote.

This box has been up and running for around 3 years and scheduled to be
superceded this summer, I have done a lot of patching on it over the years
and need to keep it up for another 4 to 8 weeks.

Recently because I was running out of space in the partition I went into the
/boot section and deleted a lot of really old versions of the kernel.  I
guess this has screwed some index up.  They are still listed in the boot
menu.  

Any ideas on how I clean this up?  I am terrified to reboot it. (Thank
heaven for my UPS)

Thanks in advance.

Chris S.