Yes, there is an issue with the VCCH_GXB power that is reported in the Stratix® IV EPE version 10.1SP1 when using 1.5V.
If you are only using a 1.5V power supply for VCCH_GXB, there may still be a current value shown for 1.4V. The 1.4V VCCH_GXB supply current should be zero, however, the EPE assumes unused channels are powered by 1.4V. If you have any unused channels, the EPE will report a small current value for 1.4V VCCH_GXB.
When only using a 1.5V supply for VCCH_GXB, you should ignore the current value reported for 1.4V VCCH_GXB.
This issue is scheduled to be fixed in a future version of the EPE.