Sonar X1 and the VS-100 - compatibility?

There are, for sure. Here are the issues listed in Sony/Cakewalks info for the drivers for win7 64: "Caution when using the Windows 7 64-bit Edition In order to use this product with the 64-bit Edition of Windows 7, please read and understand the following points. You must also take into account the compatibility of each product you will be using. In order to use the 64-bit Edition of Windows 7, you must use 64-bit drivers; not only for this product, but also for all hardware you're using with your computer. This driver has been tested on several computer systems, but please understand that we cannot guarantee it will operate on your particular computer. Cautions and Limitations Sound interruption or other less-than-perfect outcomes may be experienced if your computer's performance and specifications are somewhat inadequate. The types of applications you use and the way in which you use them can also influence the experience you receive. On some computers, the driver does not load correctly if the VS-100 is already connected when Windows is started up. As a result, it will not be possible to use the VS-100 via USB. If this occurs, wait until after Windows has started to turn on the power of the VS-100 (or to connect it). If the VS-100 does not work correctly after resuming from Sleep mode, you should exit all applications that use the VS-100, and then turn the power of the VS-100 off and on again. If the USB cable is disconnected and reconnected while the VS-100 is in use, or if the power of the VS-100 is turned off, then on again, it may stop operating correctly. If this occurs, after resuming, you should exit all applications that use the VS-100, and turn the power of the VS-100 off, then on again. If your computer was experiencing a heavy processing load, such as when accessing a CD-ROM Drive or network while the VS-100 was being used, the VS-100 may no longer operate correctly. If this occurs, stop the playback or recording, then try starting playback or recording over again. If you are still unable to play back or record, quit all programs that are using the VS-100, then turn the VS-100 off and then on again. Audio clicks and pops may occur during playback or recording if you connect or disconnect other USB devices (such as USB memory) or turn another USB device on/off while using the VS-100. In some cases, you may not obtain the expected level of performance if you're using a USB-connected hard disk at the same time as the VS-100. Do not use a USB-connected hard disk as the storage destination for the audio that you're playing back or recording." I had problems even to boot the system but finally got it solved: http://forum.cakewalk.com/tm.aspx?m=2400779 It works fine now.