Dr Byte ,
Many thanks for your support , really appreciated ....and I did manage to fix it .
however I found out somthing wrong lately , my site is working well using IE7 , but comes with empty page / ask me to download a php files while using FIREFOX , could you please clarify what is going on now :S ...?

I did use Cache Settings Synchronization Tool , but i was getting errors like below , does this cause my site to be not working with FIREFOX ?
THANKS AGAIN >>>>

Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /usr/home/xxxx/public_html/fix.php:43) in /usr/home/xxxx/public_html/includes/functions/sessions.php on line 108

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /usr/home/xxxx/public_html/fix.php:43) in /usr/home/xxxx/public_html/includes/functions/sessions.php on line 108

Warning: Cannot modify header information - headers already sent by (output started at /usr/home/xxx/public_html/fix.php:43) in /usr/home/xxx/public_html/includes/init_includes/init_templates.php on line 72

Cache Settings Synchronization Tool
Recommendations
Possible appropriate cache directory for your site is: /usr/home/xxxx/public_html/cache


Actual Information
Read DIR_FS_SQL_CACHE from configure.php: /usr/home/xxxx/public_html/cache
Found SESSION_WRITE_DIRECTORY in database: /usr/home/xxxx/public_html/cache

No changes required.
Exiting.

Security
PLEASE DELETE THIS FILE FROM YOUR SERVER NOW!!
Removing this file (fix.php) from your server protects you from would-be hackers/predators who might seek to compromise your server.