Yes it is a bug. I have latest Tk, and I tested, see Re^3: Dialog box Binding issue.

Try for yourself (tab over to cancel, hit enter).
Tk::messageBox 

perl -MTk -e"print tkinit->messageBox(qw, -default ok -type okcancel ,
+)"
Cancel

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Tk::MsgBox 
perl -MTk -e"print tkinit->MsgBox(qw, -default ok -type okcancel ,)->S
+how"
Assuming 'require Tk::MsgBox;' at -e line 1
cancel

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Tk::DialogBox (expected cancel, returns ok) 

perl -MTk -e"print tkinit->DialogBox(qw, -buttons , , [qw, ok cancel ,
+])->Show"
Assuming 'require Tk::DialogBox;' at -e line 1
ok


perl -MTk -e"print tkinit->DialogBox(qw, -default_button ok -buttons ,
+ , [qw, ok cancel ,])->Show"
Assuming 'require Tk::DialogBox;' at -e line 1
ok

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Changing the default to cancel, then tabbing over selecting ok, and hitting enter, produces cancel, its a bug 
perl -MTk -e"print tkinit->DialogBox(qw, -default_button cancel -butto
+ns , , [qw, ok cancel ,])->Show"

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Wx (wxYES is 2, wxNO is 8, and it returns 8 as expected). 
perl -MWx=wxYES,wxNO -e"warn wxYES;warn wxNO; die Wx::MessageBox( 1 , 
+2, wxYES|wxNO )"
2 at -e line 1.
8 at -e line 1.
8 at -e line 1.

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In reply to Re^4: Dialog box Binding issue by Anonymous Monk
in thread Dialog box Binding issue by Anonymous Monk

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