hi guys at first i have to say my English is not good. BUT!! i'll try to explain what i want to say as much as my English permits. Okay. after 0.21 update, i launched a mapping satellite for searching kethane reserves on the minmus. when the satellite sits on its ortbit i seperated satellite's transfer stage. i hope you understand what i mean. anyway, when the satellite and transfer stage are seperated i pressed the switch (between close vessels) key to switch to and control transfer stage for deorbiting. i did a deorbit burn and trasfer stage gone down. then i went back to space center. when i click on tracking center i saw the grid map was not working. i selected the mapping satellite and clik fly button then i saw the same thing. in the map screen grip map was not working. after some experiments i figured out why the grid map disappears. it's not about the mechjeb. it's about switching between vessels. when you switch by pressing switch key or in the map screen selecting "switch to" button, map screen runs a little bit buggy. and grid map disappears. so if we press esc and go back to space center, then tracking center and then select the vessel that we want to switch to and theenn click fly. that means dont use switch key or "switch to" button. always switch between vessels by going tracking center. sorry for bad english again. i hope you understand.