compatibility apache 2.0.48 php 4.3.4

I buyed a domain space (hosting) that support apache 2.0.48 + php 4.3.4
can i have compatibility problems??
I installed WordPress, i can see the homepage at http://www.officialsm.net/photoblog/index.php, i can post, but if i try to upload a GIF or JPG file, it say to me that have upload successfull the file, but when i clik to POST, i have this error code:
Warning: Cannot modify header information – headers already sent by (output started at /web/htdocs/www.officialsm.net/home/photoblog/b2-include/b2functions.php:1004) in /web/htdocs/www.officialsm.net/home/photoblog/wp-admin/b2edit.php on line 166
Could you help me??
Thanks in advance