Everything is in the title: when you want to unzip an ODF or OOXML file, there is no bash completion for those documents types. I hacked the /etc/profile.d/complete.bash file of my Suse box to make it work.

Here is a first diff which can be improved to support other file extensions:

--- complete.bash   2008-06-09 14:21:12.000000000 +0200
+++ complete.bash   2009-07-02 19:04:41.000000000 +0200
@@ -162,8 +162,7 @@
    esac                            ;;
     gunzip)        e='!*.+(gz|tgz|z|Z)'            ;;
     uncompress)        e='!*.Z'                ;;
-    unzip)     e='!*.+(???)'
-           t="@(MS-DOS executable|Zip archive)*"   ;;
+    unzip)     e='!*.+(zip|ZIP|o[dt][tspgf]|O[DT][TSPGF]|doc[xm]|DOC[XM]|xlsx|XLSX|pptx|PPTX)';;
     gs|ghostview)  e='!*.+(eps|EPS|ps|PS|pdf|PDF)'     ;;
     gv|kghostview) e='!*.+(eps|EPS|ps|PS|ps.gz|pdf|PDF)'   ;;
     acroread|[xk]pdf)  e='!*.+(pdf|PDF)'           ;;