problem with shared object file

Hello, I'm trying to include a shared object file with the function dl(). But I always get: Warning: dl() [function.dl]: Unable to load dynamic library '/homepages/xyz/util.so' - /homepages/xyz/util.so: cannot open shared object file: No such file or directory in /homepages/xyz/test.php on line 5 But it is definetely there and readable (also executable)! I tried to include('/homepages/xyz/util.so') which gives same parsing errors since this is not php-code, but including works, so it's actually readable. What is the real error behind it? How can I find out why dynamic loading fails? Is it possibly due to different glibc versions? Regards Marten