Everyone, I have a centos 5.10 machine set up to be a fax server using hylafax+ with three multitech MT5634ZBA modems. I am still in the testing phase of using this system for production, and during my tests I have detected a problem I have not been able to solve except for unplugging the modem from the usb port and plugging it back into the usb port. In the middle of a fax production of around 1,000 faxes the ttyACM0 device becomes disabled and disappears. I have only had this happen twice so I have not collected sufficient data to figure out what is happening. When I remotely reboot the os, the system comes up and ignores the modem that has become faulty, and of course ttyACM0 is assigned to a different modem. Has anyone had problems with the MT5634SBA modems, and if so what modems would you recommend by way of replacements. Is there a way to turn off a usb port so that I could power down the modem remotely, and then bring it back up. I think if I could do this, remotely, I may be able to save the use of these modems. Otherwise, I am going to be required to have someone unplug the modem and plug it back in to reset it in order to make it work. hylafax+ seems to be working fine, it just reports that the modem has become inaccessible. Any ideas? Thanks much, Greg Ennis