Today I solved one of the topics mentioned in "Liferea Development Failures" post: the Flash content removal.
With the yet to be released 1.4.24 and 1.6-RC1 the default behaviour will be to strip Flash embedding tags from the feed content. The rationale is to prevent freezes and crashes due to Flash player issues. So if you upgrade you won't see Flash anymore...
...unless you enable it in the preferences as shown in the screenshot below.
I hope this will help everyone having a XulRunner-Flash setup to tends that crash/freeze and all those using Webkit and having problems with the DSP device locking.