The paused or unpaused state is supposed to be saved with a stamp (either a ctrl+c copy, or a S stamp save). Yet in the latest beta version, and the full version that came from it, this pause state in is no longer saved, requiring you to pause it manually prior to pasting, in order to set or remove the pause state.

After pressing S or ctrl+c, it used to be possible to change the pause state prior to making a selection. In the last beta, and the resulting current full version, this is no longer possible.

Any WALL type objects now have significant amounts of them disappear spontaneously when rotating a stamp (ctrl+r) or flipping it (ctrl+shift+r) prior to clicking to finalize the paste. This may be the last one I listed, but it is by far the most significant, and detrimental to use of the program, as it impairs the use of a large portion of stamp functionality.