I'm not familiar with Cubase AL6, but the CMC comes with AI6, so it should work with that. There is an update 6.0.7 to AI6, not sure if this affects the CMC. On the other hand you might try downloading the trial version of 7.
Further than that I suggest, if the problem continues, that you use an easily reproducible example and describe step by step, the procedure you're trying to follow.
...yes I think it can be easily done, just take everything down to Highway 61.Sun Point Studio Turbenthal, SwitzerlandCubase 7.5.20 - 64bit | WaveLab 8 - 64bit | PT10 | UR28M | CMC-PD/4xFD/QC/AI/CH/TP | BCF2000 | Shuttlexpress | Graphire Tablet | Cubendo Custom Keyboard | Lenovo E31 Workstation:Xeon E3-1225V2/3.2GHz; 8GB DDR3 SDRAM; 2x Intel-Flash520 SSD 180GB (C:/D:);1TB 7200rpm Sata3 (F:); DVD RW (E:); Ext. 3TB USB3 Freecom + WD 1TB; Nvidea GeForce GT 630 4GB DDR3 Video Ram AGP PCIE | Win 7 Pro 64 Bit