Can't select Dinkum libs with Momentics IDE

I am trying to link my C++ application agains the Dinkum libs (-Y_cpp) but changing
the appropriate option in the project properties dialog does not stick (i.e. I select
“Dinkum with exceptions”, but when I select “Apply” then “OK” then go back into
project properties, the selection has returned to “Link against → Default”.

What’s up ?