Screenshots don't work with Shift/Ctrl if key is SYSRQ

When the key for screenshots is set to "SYSRQ" (usual description is "PrintScreen", I think), it's not possible to create a screenshot with Shift+Sysrq, Ctrl+Sysrq or Shift+Ctrl+Sysrq. It's not dependent on whether Shift or Control are bound to any action in MC.
Alt+Sysrq and Alt Gr+Sysrq key work.