Syntax Highlighting bug "Selected text"

I´m trying to change the background color of the "Selected text" in my Syntax Highlighting color sheme. But what ever I do, all the selected text turns black.

In the Color sheme editor it is enough to just select "Selected text" click on the color and then click OK (without even changeing anything there). The Alphachannel is broken and the text is all back.

I exported the sheme to an xml file and also an unedited version and compared them. the unedited version stored the color as color="#00000000", my version as color="#000000". I put the additional two zeros for the alpha channel back in, saved the file and imported the sheme, but it is still being ignored.

Does anybody know of a way how I can change the color for "Selected text" without breaking the alpha value?