<hr /><i>martin.weber added on 2011-08-22 15:29:33 UTC:</i><br />
Yes, I can see this, too, with at least

$ fossil version
This is fossil version 1.18 [df9da91ba8] 2011-07-13 23:03:41 UTC

Also the transcript is very interesting:
<verbatim>
$ ./tst.sh
project-id: 6bc2abb2549099cdc849e19c269d8ead14bd6113
server-id:  e4843abba50a452aefa3d5a102eb96481be4fba4
admin-user: phaeton (initial password is "41ba40")
ADDED  some-file
New_Version: ffdb5f97e8190eaa0564af8845acf05f5f4cd6fc
-rw-------  1 phaeton  users  0 Aug 22 11:27 some-file
After rm: some-file is not there.
repository:   /data/home/phaeton/tmp/ftst/banzai.fossil
local-root:   /data/home/phaeton/tmp/ftst/open/
server-code:  e4843abba50a452aefa3d5a102eb96481be4fba4
checkout:     ffdb5f97e8190eaa0564af8845acf05f5f4cd6fc 2011-08-22 15:27:20 UTC
parent:       9a89746aa0dec33acf90d3375e8f828b836dae36 2011-08-22 15:27:20 UTC
tags:         trunk
comment:      added some file (user: phaeton)
MISSING    some-file
After fossil update: some-file is not there.
repository:   /data/home/phaeton/tmp/ftst/banzai.fossil
local-root:   /data/home/phaeton/tmp/ftst/open/
server-code:  e4843abba50a452aefa3d5a102eb96481be4fba4
checkout:     ffdb5f97e8190eaa0564af8845acf05f5f4cd6fc 2011-08-22 15:27:20 UTC
parent:       9a89746aa0dec33acf90d3375e8f828b836dae36 2011-08-22 15:27:20 UTC
tags:         trunk
comment:      added some file (user: phaeton)
MISSING    some-file
UPDATE some-file
--------------
updated-to:   ffdb5f97e8190eaa0564af8845acf05f5f4cd6fc 2011-08-22 15:27:20 UTC
tags:         trunk
comment:      added some file (user: phaeton)
"fossil undo" is available to undo changes to the working checkout.
repository:   /data/home/phaeton/tmp/ftst/banzai.fossil
local-root:   /data/home/phaeton/tmp/ftst/open/
server-code:  e4843abba50a452aefa3d5a102eb96481be4fba4
checkout:     ffdb5f97e8190eaa0564af8845acf05f5f4cd6fc 2011-08-22 15:27:20 UTC
parent:       9a89746aa0dec33acf90d3375e8f828b836dae36 2011-08-22 15:27:20 UTC
tags:         trunk
comment:      added some file (user: phaeton)
EDITED     some-file
fossil: there are unsaved changes in the current checkout
</verbatim>
Look at the last two lines. After doing nothing more than an update, fossil thinks some-file has been EDITED where it's not. It's an empty file, just like the one that has been added.