Some people who tested Slackware-Current ISO have reported that the installation will hang during bind installation (thread can be followed at LQ). Today, a (possibly) fix has been released on -Current. If we look at the changelog which is very short (only one line), this might be the solution to fix bind problem during installation.
Here's the changelog:
Sat May 23 03:27:41 CDT 2009 n/bind-9.4.3_P2-i486-2.txz: Use /dev/urandom to stop blocking on install.