A booting problem-sometimes

Occasionally when I turn on my computer with XP SP2, it boots into the desktop with about half the icons missing and then it stops booting. To continue I have to hold down the on-off button which turns it off and then restart it, and it boots all the way. When it stops booting it happens before the icon displaying the LAN connection appears in the taskbar The NAV icon appears afterward in the normal boot. Anyone have any idea why the booting stops?

 

Is this a recent phenomenon? Any hardware/software changes shortly before it started? Any clues in event log (run eventvwr.msc)? Up to date anti-virus and anti-spyware running? Not too much starting up when you boot (have a look in msconfig)?

 

I looked at the event log and apparently this seems to be related to the loading of SeaMonkey in the startup programs. I checked a box in SeaMonkey preferences to load it at start up so that it starts faster. This problem is recent but if it persists I will stop the start up loading of Seamonkey.
Thanks for your suggestion.