The BEAST!

<runs away screaming....>

Not enough information to say anything definite, but I would guess malware.

Do a thorough check for malware following all of the steps at one of these
sites:
Help with malware
All  MS-MVP Sites.
http://aumha.org/a/parasite.htm
http://aumha.org/a/quickfix.htm
http://www.elephantboycomputers.com/page2.html#Removing_Malware
http://mvps.org/winhelp2002/unwanted.htm
http://inetexplorer.mvps.org/darnit.html
http://www.mvps.org/sramesh2k/Malware_Defence.htm

Unexplained computer behavior may be caused by deceptive software.
http://support.microsoft.com/kb/827315

So How Did I Get Infected Anyway?
For quite a few people it's by installing Messenger Plus, whose ads for
malware don't identify the malware as such and try to convince you that you
owe it to the author.  See also:
http://www.wilderssecurity.com/showthread.php?t=27971
Don't ever do a "default" install of anything.  Always choose Custom and see
what else is being carried along.  Don't install any extras you're not sure
of.

Instead of saying "certain links" (which doesn't tell anybody anything)
post details about them.   666 vaguely suggests that you are doing
something with POP3 E-mail messages with UUEncoded attachments
inside.   In that case it would be related to the original permissions
of the file (when seen on an UNIX system.)   Etc.

---

Hello. Thanks for your helpful replies. I could not make the problem re-occur
this morning. Maybe Windows "defender" took care of business during the
night. I also have as protection Spy Sweeper, Spybot, and Norton Internet
Security all of which I am accustomed to running frequently on my old messed
up XP machine. Seems AdAware(free) is not ready for Vista yet.
For informational purposes, I believe the glitch ocurred when I tried to cut
and paste a link beginning with "http://anonym.to/?"( which I think is a link
protector ) into the address bar in IE7. That is when I got the blank page
with "666" on it.
Anyway it hasn't happened again, But I will post a note if it happens again.
Please post any further thoughts on this as I am eager to prevent it from
happening again. ( I know! Don't go there!) Any and all help is welcomed.
Thank you