Strange problem with PHP 5.1.x and MySQL 4.1.x

Hello all,

after updating MySQL to 4.1.20 on my Linux server, I started having some slight problems with PHP 5.1.4 connecting to it. Before upgrading MySQL to 4.1.20, I had PHP 5.1.4 and MySQL 4.0.27 installed. Everything worked fine.
After upgrading MySQL to 4.1.20, I had to downgrade PHP to version 4.4.2. With PHP 5.1.4 all scripts that used the mysql_connect function stopped working and the browser prompted to download them. (and if I clicked ok, actually, a zero bytes php file was downloaded). Even a simple php file with only one line:
mysql_connect("localhost", "username", "password");
prompts me to download it. All other scripts (not using a MySQL connection) worked fine in PHP 5.1.4. I double checked the httpd.conf and php.ini but nothing strange was there. After downgrading to PHP 4.4.2, all the scripts where again working fine with MySQL 4.1.20. I tried reinstalling MySQL, PHP 5.1.4 but this didn't help.

So, here is a conclusion:
- PHP 4.4.2 and 5.1.4 working fine with MySQL 4.0.27
- PHP 5.1.4 doesn't work with MySQL 4.1.20 (all .php scripts containing the mysql_connect function, are parsed blank and prompt for download, no error about undefined function or failed connection... just a blank page).
- PHP 4.4.2 works fine with MySQL 4.1.20 (this is what I have done now, so my sites are online, but I would prefer using PHP 5.1.x again).

I tried compiling PHP 4.4.2 and 5.1.4 with these options:

and without "--with-mysqli" but in both cases the problem persisted: PHP 4.4.2 connecting fine to MySQL, but PHP 5.1.4 not

Any ideas?
Thanks in advance

Edit: ok, now the problem is fixed. What I did (if somebody ever needs it) was deleting the whole php directories before doing a recompile and reinstall of PHP 5.1.4 (very strange, usually it was not needed till now, when I upgraded PHP or MySQL, ie. I had not deleted the php directories when I had upgraded from PHP 4.4.2 to 5.1.4). Probably there were some old files left there, causing problems with MySQL 4.1.x connections, even after a recompile and reinstall. Finally, everything works ok now with PHP 5.1.4 and MySQL 4.1.x