I you experience FVE hangs, crashes and freezes there is a little workaround until I get created the right counter measures.
Try uninstalling the current version of FVE and go back to version 4.0.21. It has some issues with returning gifts for some SDB’s but it will not make FVE hang/freeze.
Uninstall this way:
http://getsatisfaction.com/fv-extender/topics/how_to_disable_or_uninstall_fv_extender
Install 4.0.21 from here:
http://a-creative.github.com/FV-extender/versions/release_4_0_21.crx
(click the link inside Google Chrome or it will not work)