OpenSSL error

Hi

I develop a system using OPenSSL for Rijndael-256 (RSA-256) encryption. It works weel on an Apache server with PHP 5.3.2 on Windows and on a Linux server.
But, on a Mac, I experience a weird problem.
When I send a block to be decrypted, it works some times, and, without any reason, it stops and stays blocked for a while. And suddenly, it works again.
When it crashes, I have the error message :

Wrong request for connection error:0906D06C:PEM routines:PEM_read_bio:no start line

I searched on Google and couldn’t really find any solution. I read it seemed to be related to the keys format.
The public key used for encryption is like :


-----BEGIN PUBLIC KEY-----
...
-----END PUBLIC KEY-----

And the private is like :


-----BEGIN RSA PRIVATE KEY-----
...
-----END RSA PRIVATE KEY-----

Has anybody met that problem before and/or know where it comes from and how to fix it ?

Thanks