On my Win XP version of 4.5.2 RC1 (PMSetup4.5.2b0727.exe) this problem is present. All of the items on the toolbar to the right of the thumbnail size slider are not present. I also noticed this in the prior beta version.
On Windows, if you relaunch PM with the Shift key down, all layout settings will revert to their default settings.
-Kirk
Unfortunately pressing the shift key at startup has no effect (does the beta message box get in the way perhaps?). There doesn't seem to be any way to get the tools back on the toolbar. And since there is no other way to sort a contact sheet, i.e., via a menu item, this has become a major issue.
(BTW, shouldn't there be a menu item for sorting somewhere?)
More info after more testing:
Undocking and redocking does eventually get the tools back as indicated in the top post. However, it took a couple of tries. But when I restart PM (without the shift key pressed) the tools disappear again.
Thanks.