USB-modem problems

hello, I installed Suse-Linux8.2 and my USB-modem does not work properly. After booting it connects me only one time to the internet. I have to pull the USB-plug out and in to restart the hotplugging system, and then I can connect one more time again. I thought it depends on the /etc/sysconfig/hotplug . I added the module "acm" to : HOTPLUG_USB_STATIC_MODULES="evdev joydev mousedev acm" KInternet Protokoll (ifcfg-ppp0.cfg) says: pppd: --> stdin not read/write and $MODEM not set How can I solve this? Is there a way to restart the hotplugging system without pulling plugs? regards Olaf Cammerzell