I put this in Asterisk since Zaptel is inevitably part of Asterisk. Feel free to move it. That said, I also apologize if this is re-hashing something, but the posts I found noted the issue but did not resolve it. If a solution is known, I'll be happy to hear it. I've successfully run Elastix with CentOS 5.1 and 5.2 under VMWare Workstation 6.5 on a Windows XP SP3 32-bit host with an AMD FX-60 64-bit CPU. I tried to set up Elastix under Xen 3.0.3 (paravirtualized) with a CentOS 5.2 32-bit host (Dell PE2650) and ran into a kernel panic with both CentOS 5.1 and 5.2 running the kernel-xen that was recommended in the how-to. I haven't been able to capture the exact panic because the system toasts the VNC link too fast. I tried re-compiling the zaptel module to the same effect. If I boot with another kernel that doesn't have Zaptel, everything boots fine, but of course, no zaptel. I don't need any Zaptel card support, but was under the impression the dummy timing thing was important. Has anyone come up with a solid solution/combination of kernel and zaptel and xen 3.0.3 (paravirt) to make things work?