Yes 1.4.23.1 does have a bug with pickup. call pickup fails as described in bug.
But for clarifaction for people searching the forum , This issue is that when you try to do a pickup using the code in the features.conf the called extesnion stops ringing but the call isnt picked up.
The best approach is to upgrade 1.2.24-rc1 is out and it fixes this problem.
if you can really show how to apply such patches on existing (in production) systems it would be great and nice of you.
also if some one could show a way to upgrade from an earlier release to newer release without affecting existing configuration it would really help us newbies.