Platforms: Windows XP SP3 & Windows 7 SP1 xp64
java Version: 1.7.0-09
Steps to reproduce:
1) Install a clean copy of 5.0pre1 with no plugins other than those that come with 5.0pre1.
2) Use the default settings for backups.
3) Edit a text file.
4) Save changes and exit jEdit.
Expected result: A backup copy of the text file in the directory containing the original text file.
Actual result: No backup copy.
I also found this behavior on 5.0pre2 and the most recent nightly build.