This is old actually old news, but I suspect some people have forgotten or maybe do not understand to what extend. We decided to break overrides in 2.5.0~rc1, as explained in Raphael’s email to email@example.com.
As the email mentions there were two breakages – the tag merges and the file prefix change. Especially the latter seem to be causing confusion (or at least pings/questions/emails for me). The long story short:
All overrides listing files with a prefix of “./” or “/” will not work as of 2.5.0~rc1
If you are curious as to why, please have a look at #534940.
Fixing the override is simply a matter of removing the “./” or “/” prefix(es). If you discover a tag that still uses “./” or “/” as file name prefix, please file a bug (assuming someone did not beat you to it).
I am not entirely sure if the FTP-masters have updated the copy of Lintian that handles auto-rejects, so you may have keep the old/broken override if it is for a non-fatal auto-reject tag. This is especially true for the embedded-zlib tag that were merged into embedded-library.
 On a related note, this is why this is 2.5.0~rc1 and not 2.4.4.
 I also do not know when they plan to do it if they have not already done so, but Tolimar has informed me that 2.5.0~rc2 is in squeeze-backports. >.>