Mysql built in but says it isn't

Hello to all - first of all thanks for this gateway, it's my first day using it and I'm actually able to send
sms messages with 3 smsc, so thanks a lot to devlopers!

Here is my problem:

Using the directive: dlr-storage = mysql

I get:

bearerbox smskannel.conf
2004-01-08 04:46:51 [0] INFO: Debug_lvl = -1, log_file = <none>, log_lvl = 0
2004-01-08 04:46:51 [0] DEBUG: Loading include file `ucp-mysql.log' (on line 41 of file smskannel.conf).
2004-01-08 04:46:51 [0] PANIC: DLR: storage type defined as 'mysql', but no MySQL support build in!
2004-01-08 04:46:51 [0] PANIC: bearerbox [0x80ce7f8]
2004-01-08 04:46:51 [0] PANIC: bearerbox [0x80558e6]
2004-01-08 04:46:51 [0] PANIC: bearerbox(vfprintf+0x1566) [0x804b502]
2004-01-08 04:46:51 [0] PANIC: bearerbox(__libc_start_main+0x95) [0x42017589]
2004-01-08 04:46:51 [0] PANIC: bearerbox(tcgetattr+0x65) [0x804a4f1]

[CUT] (server dies)

While if I use the directive: dlr-storage = internal 

bearerbox smskannel.conf
INFO: Debug_lvl = -1, log_file = <none>, log_lvl = 0
2004-01-08 04:44:43 [0] DEBUG: Loading include file `ucp-mysql.log' (on line 41 of file smskannel.conf).
2004-01-08 04:44:43 [0] INFO: DLR using storage type: internal
2004-01-08 04:44:43 [0] DEBUG: Kannel bearerbox version `cvs-20040106'.
System Linux, release 2.4.18-3, version #1 Thu Apr 18 07:37:53 EDT 2002, machine i686.
Hostname linkas-mam, IP 127.0.0.1.
Libxml version 20419.
Using MySQL 3.23.58.
Using native malloc.
2004-01-08 04:44:43 [0] INFO: SSL not supported, no SSL initialization done.
2004-01-08 04:44:43 [0] INFO: HTTP: Opening server at port 13000.

[CUT] Server start

My question
------------------

How comes it sees MySQL (while dlr internal) but says it's not built in ?

NOTES:
1) I had to modify my Makefile under Redhat 7.3 to delete the -lz as it gives me error saying: /usr/bin/ld: cannot find -lz
2) my configure line is ./configure --enable-mysql --disable-wap
3) I'm under Redhat 7.3