Saving a mission file leads to duplicates?!?

Hi,

sometimes, in TGEA 1.8 we noticed a strange behaviour: After playing around with our missions and saving the resulting world, the mission file contains two object lists like this

//--- OBJECT WRITE BEGIN ---
...
...
//--- OBJECT WRITE END ---
//--- OBJECT WRITE BEGIN ---
...
...
//--- OBJECT WRITE END ---

where the first list seems te be the old one and the second is the "new" world. This is quite bad because most objects (items, terrain sky etc.) are renderes twice which drops the frame rate.

Is this a bug or a back-up feature? How can we disable this?

Thanks and best regards,

Tobias