On the matrox boards :
http://forum.matrox.com/mxo/viewtopic.php?t=13229
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To all Matrox MXO2 Family, Mojito MAX, and CompressHD users,
Mac OS X Mavericks 10.9 update is not compatible for use with Matrox MXO2 Family, Mojito MAX, and CompressHD software drivers. We recommend that you keep your current supported Mac OS X version for use with MXO2 Family, Mojito MAX, and CompressHD hardware.
We are currently testing and evaluating future 4.x Matrox drivers to provide support for Mac OS X Mavericks 10.9 with MXO2 Family, Mojito MAX and CompressHD products.
Thank you for your understanding.
-Matrox Video Technical Support
hopefully soon!
chris