I found a bug report about the mirrored text in the settings. It's quite old so the bug probably doesn't get fixed any time soon but I can try the workaround which at least should make the text flow the right direction.
I guess it's something, but just to inform you, there are other major bugs when using RTL languages in rainlander that are not connected to that wxpropgrid addon, like in the Events and the "TO DO" lists where the text start from left to right instead of right to left making a lot of mess.
even the order of the months and days in the main calendar is inverted. counting from left to right.
those problems block rainlendar's exposure to RTL reading audience. we talking about alot of people here..