[Orgmode] Agenda clock report does not follow links via keypress

[Chris Leyon]

When I generate a clock report in the agenda, the Headline column
contains things that *look like* Org links.  I can mouse-1 or mouse-2
on them and the corresponding items pop up correctly.  But if I move
point onto one of these and press Return, I am told "Command not
allowed in this line", even though org-return-follows-link is t.  If I
press `C-c C-o', I get "Wrong type argument: number-or-marker-p, nil".
 I am using org-version 6.32 on GNU Emacs 23.1.