I've noticed that some of the rtmpdump-dependant addons for XBMC 11.0 have been written for rtmpdump-2.4 rather than 2.3 (the unofficial Hulu and Free Cable addons in particular). These addons won't run unless rtmpdump is upgraded, or rather will run, but won't retrieve content.
There's no slackbuild yet for rtmpdump 2.4. And 2.4 source hasn't been placed yet in the archive at http://rtmpdump.mplayerhq.hu/download/
but current code apparently needs to be gotten with a git pull.
So for XBMC functionality with these addons requiring rtmpdump-2.4, it appears that the slackbuild compile of rtmpdump needs to be upgraded with current 2.4 source, or the slackbuild rtmpdump package can be upgraded with the rtmpdump-2.4 package provided by the SlaXBMC project, which was the course I took and it seems to run fine. http://slaxbmc.blogspot.com/2012/01/...de-beta-1.html
If any version of rtmpdump was installed prior to the XBMC slackbuild having been run, then simply upgrading rtmpdump to 2.4 is sufficient. But if no version of rtmpdump was installed at the time when the slackbuild script for XBMC 11.0 was initially run, then the script will need to be run again after rtmpdump-2.4 is installed to enable 2.4 support in the compiled xbmc package.