[Therion] Colours in area fill patterns replaced with black

Here's a bug that's been annoying me for a while: In recent (5.2.11 and newer) versions of Therion (on WinXP sp3), colours used in area fill patterns are replaced with black. The simple test case attached demonstrates the effect: In v 5.2.10 and earlier, you get a square filled with a red cross-hatch pattern, while in 5.2.11 and later the fill pattern is black. I initially suspected that the change from Metapost 0.641 to 1.201 bundled with the Windows install of Therion might be to blame as I first noticed this bug around that time, but a little testing indicates that both Therion 5.2.9 and 5.2.10 use Metapost 1.201 and don't exhibit this bug. Duncan.