apache/php: chunk is already free, page is already free

We made a test for only 20 min. and got our website online. The result was 200.000.000 (!!) lines in apache error log with the following: httpd in free(): warning: chunk is already free. httpd in free(): warning: page is already free. httpd in free(): warning: recursive call. the requests were only made by myself (30 times). letting the website online for 4 hours produced an apache error log of 21 GB !!! and some zero sized responses from apache :) using openbsd 3.2, apache 1.3.26 and php 4.2.3. the website is a forum using phorum.org software and has a mysql database (about 300 MB) after googling about this I know that only a few people have the same problem but couldn't solve it. Most of them say, that this is a memory issue of php (some of them used older versions like php 4.0.6). I also dont think that the problem is because of phorum.org software, apache or mysql. Maybe openbsd? on the same server there are a lot of other hostings without any problems. Any hints or links? thanks ergin