System tasks and functions allow NULL arguments, This patch fixes the @* sensitivity list code to handle this correctly. There is a patch for both development and V0.9 along with one for V0.8.
I'll push the test code shortly.
Development and V0.9 patch file.
V0.8 patch file
Applied to git master.
Applied to git v0_9-branch.
Applied to git v0_8-branch