problem with nmap (please help)

[Diet54 () aol com]

i have this version of nmap (nmap-3.81-win32). im running windows xp and i 
just installed new beta of winpcap (WinPcap_3_1_beta4). when i try this command 
in nmap...

-----------------------------------------------------
nmap -A -T4 scanme.insecure.org 
----------------------------------------------------------- 
i get this message...

------------------------------------------------------------------------------
------------
Starting nmap 3.81 ( http://www.insecure.org/nmap ) at 2005-03-13 06:47 
Eastern
Standard Time
Note: Host seems down. If it is really up, but blocking our ping probes, try 
-P0

Nmap finished: 1 IP address (0 hosts up) scanned in 5.969 seconds
------------------------------------------------------------------------------
----------------

even if i try to ping (scanme.insecure.org) using the command below i still 
get host not found. but if i do a (ping scanme.insecure.org) i get a ping 
replys back. i dont know whats going on. 

-------------------------------------------------------------------
C:\nmap>nmap -sS scanme.insecure.org

Starting nmap 3.81 ( http://www.insecure.org/nmap ) at 2005-03-13 06:50 
Eastern
Standard Time
Note: Host seems down. If it is really up, but blocking our ping probes, try 
-P0

Nmap finished: 1 IP address (0 hosts up) scanned in 6.329 seconds
-----------------------------------------------------------------------

i can never get any verion of nmap or netcat to work on this computer. ive 
been trying for over a year. i emailed foundstone a few times asking for help 
with they 2 programs.. and they never got back to me. its pissin me off i want 
touse these programs. and when i set up my network i want to be able to use the 
programs. why do i keep getting host seems down.. its driving me crazy. is 
their something i have to do to get it to work.. install some patch or 
something.
PLEASE PLEASE try to help me
get back to me asap.. thanks

:)