FC2 boot problem

[Paul Murtaugh]

My desktop has been running FC2 with no problems, until
the screen froze this a.m. and I had to re-boot.   As it 
was starting up, I noticed there were three kernel options 
-- I think it must have yum-updated the kernel last night 
(I usually keep two kernel versions on hand).  However,
the following problem happened whichever kernel I chose.
                                                                                       
It would get to the 'Welcome to Fedora' screen, and
then go blank with the hourglass -- as you usually see
before the various services get started.  But it would go 
no further; every so often the screen would refresh, but 
the blank screen with hourglass would re-appear, ad 
infinitum.  It doesn't get to the screen with the progress
bar and 'Show details' option, so I have no idea how to
begin debugging this problem.
                                                                                       
Any suggestions on where to start would be greatly
appreciated!

-Paul