Just yesterday I tried the slacke17 packages (Feb 02,2011 version):
All looked well until I clicked on the desktop to open the applications menu. When I moved my mouse over the list, one of the sub-menus popped up and the desktop froze. This was in my first run, but the same thing happened in my second login, too. I decided that it wasn't stable enough and uninstalled it.
I remember having installed e17 about a year ago (on a different Slack install, and it was probably from slackbuilds.org). I can't remember exactly what had happened, but there was a similar bug back then which led me to drop e17.
On the other hand I find it unlikely that the e17 guys overlooked such a trivial issue. My problem could be related to my particular hardware/software setup. Here they are: Slack 13.1, custom kernel 18.104.22.168, eeePC HA 1005 with i915 (945GME) video chip.