ASUSa7v mobo question

[bonehead]

:disgust: Help Can anyone help me with this problem? I have a ASUS a7v and a new case with the usual seven slots in the back for the pci cards ect. When i install the ASUS modem riser in the mobo slot,it dosen't line up with any rear slots in the case.It seems that i need another opening in the case for this to work below the 7th slot in the back. Pls help if you can.Thanks