1. download from http://www.fabforce.net/ I get DBDesigner4-0.5.4-0.i586.rpm

2. apt-get install rpm alien

3. alien --to-deb DBDesigner4-0.5.4-0.i586.rpm you must get a file: dbdesigner4_0.5.4-1_i386.deb

4. dpkg -i dbdesigner4_0.5.4-1_i386.deb

5. fix missing simlinks ln -s /usr/lib/DBDesigner4/libsqlmy.so /usr/lib/

6. from http://cesar.plug.org.ve/?p=41 :

wget http://www.silcom.com.pe/soft/xlibs_6.8.2-77_all.de

sudo dpkg -i xlibs_6.8.2-77_all.deb

wget http://heanet.dl.sourceforge.net/sourceforge/kylixlibs/kylixlibs3-borqt_3.0-1_i386.deb

sudo dpkg -i kylixlibs3-borqt_3.0-1_i386.deb

7. Run from /opt/DBDesigner4/DBDesigner4

8. Enjoy it

Blessings!