I'm running Tiger (10.4.11) which includes the Safari update to 3.0.4 on an iMac (late 2006 i.e. the last white version before the new aluminium/glass ones).

Version 1.5, which I've had installed for a while, works with Safari 3.0.4. I just tried it again half way through the last sentence and it works as it should. F7 - all tabs come up and you choose the one to view.

Version 1.7.1 doesn't. If I've got 5 tabs open, Safari seems to relaunch with just the first tab in place - all the other tabs disappear.

(thanks heavens I did a quick SuperDuper! backup to an external drive before installing the newer version)

So I'm back to version 1.5.