I have a command that stores some data to a Dictionary in an AutoCAD drawing. I am experiencing problems with UNDO where all the data in the Dictionary is lost. I will run the command and store the data to the Dictionary. Now lets say I run the command again to change the values in the Dictionary. If I do UNDO to revert to the previous values there is nothing left in the Dictionary after UNDO. What might cause this and how can I fix it?