(1) writing data to a file like:
echo test data > test1.txt
(2) writing data to an altinative data stream for the file like:
echo test data 2 > test1.txt:test1
(3) The content of the file is lost:
I have reproduced this. Investigating.
I tested againt Samba 3.2.6 and this bug is fixed at 3.2.6. (And not at 3.2.5)
according to the announcement: http://samba.org/samba/history/samba-3.2.6.html
* BUG 5903: Fix vfs_streams_xattr breaking contents of files.
BUG#5902 is also fixed.