I have two installations of vim: 7.4 in cygwin and 7.2 in a Linux virtual machine. The vim in the virtual machine can undo multiple edits by repeatedly pressing the u key. The vim in cygwin can only undo the most recent change. Pressing it a second time is a "redo" (which in the virtual machine can be accomplished with the Ctrl-r sequence).

I would like to get the cygwin installation to be able to undo multiple edits through repeatedly pressing the u key, like it does in the virtual machine.

I have tried comparing the features included in both installations, but I have not identified what could be causing this difference in behavior. Another post on this website suggested I could use the . key after using the u to undo multiple times, but that has not worked for me in the cygwin installation. I also haven't found any settings in the vimrc files that seem like they would modify this behavior.