FC7 Pb with the WEbpages

Hi,

I change a server from CentOS v5.2 -> FC7 ( just copy and past the HTTP
conf files )

Then I discovered that :

All the website are working perfectly !!
However, on the same LAN that the server, I always needed to call the
web like :
http://<LA_IP_Address>

Now, with Fedora, it doesn't work..
the message is :
****
Bad Request
Your browser sent a request that this server could not understand.
***

I discovered that I had a better result if I write :
http://<LA_IP_Address>:80
but when I am calling the webmail
http://<LA_IP_Address>/mail => It's a disaster... impossible to get the
webmail...

- Any idea what could be the problem ??

NB, form Outside the LAN, everything is working fine....

Thanks