I've written the scons scripts to build Yhe, but it currently fails to build for me. Can anyone explain this error message to me?

ghc -i./src/compiler98 -idepends/cpphs -idepends/filepath -i./src/interactive -cpp -c src/interactive/GuiGtk.hs -o src/interactive/GuiGtk.o

src/interactive/GuiGtk.hs:395:26:
    Couldn't match `TagName' against `Maybe a'
      Expected type: TagName
      Inferred type: Maybe a
    In the application `Just "input"'
    In the first argument of `textTagNew', namely `(Just "input")'

src/interactive/GuiGtk.hs:845:24:
    Couldn't match `TagName' against `Maybe a'
      Expected type: TagName
      Inferred type: Maybe a
    In the first argument of `textTagNew', namely `Nothing'
    In a 'do' expression: linktag <- textTagNew Nothing

I have gtk2hs-0.9.10 installed.

Andrew