1) Create a changelist
2) Shelve changes on one of the files in the changelist
3) The file disappears from the changelist
4) The patch is created
5) The VCS status in the editor tab goes to "unchanged"
6) The change markers in the file disappear
7) But the file's contents are clearly unchanged (that is to say, still have my local modifs)
8) Typing one character brings back the change markers
There don't appear to be any exceptions in the log.
I'm using SVN 1.4 under Linux, but maybe it's the same with other VCS?