About the new installation Centos 6.5 kernel 2.6.32-431.el6.i686, KDE 4.3.4, KPPP Ver. 2.4.0.
Modem IPWireless PCMCIA as /dev/ttyIPWp0 ready, ok. Driver is generically in kernel.
Modem in other pc working right.
Settings KPPP, card modem. click new modem devices /dev/ttyIPWp0 is not in list.
So, manualy edit /.kde/share/config/kppprc add [Modem0] Device=/dev/ttyIPWp0.
KPPP after connect displayed dialog as, device /dev/ttyIPWp0 can not be use. Terminal nothing to view.
Please, where should be issue?

Please check the permissions of the device /dev/ttyIPWp0 and verify that your user has permission to write to it.

Have you tried to access the modem with minicom?
Is the suid bit set on kppp (it used to fork, keep suid only on the cli slave and have teh GUI master run w/o suid, so suid should be ok)