Description
In Quartus® II software version 10.0 there is a known problem where it is not possible to set some configuration pins that are available as user I/O in usermode. This will be corrected in a future version of the Quartus II software.
As a workaround you can add the following two global assignments into your project's .qsf file. These assignments will set the DATA pins to be used as user I/O as long as the device and configuration scheme you are using will support the DATA pins being used as user I/O pins after configuration.
set_global_assignment -name RESERVE_DATA0_AFTER_CONFIGURATION "USE AS REGULAR IO"
set_global_assignment -name RESERVE_DATA7_THROUGH_DATA1_AFTER_CONFIGURATION "USE AS REGULAR IO"