LPeg and numbered capture

[Philippe Lhoste <PhiLho@...>]

I just can't seem to make it work...

The facts: on Windows 7, using Lua 5.1.4 and LPeg 0.10.2
I try something simple:

local cap = m.R('AZ')
local caps = ((1 - cap) + m.C(cap))^0
local toMatch = "Everybody's Got Something to Hide Except Me and My Monkey"
print(m.match(caps, toMatch))
print(m.match(caps / 1, toMatch))

The first call works, showing the uppercase letters.
The second call gives a runtime error:
lua: LPegPlayground.lua:5: bad argument #2 to '?' (invalid replacement 
value)

Is the numbered capture actually implemented in this version?
Or am I missing something?

This kind of capture is hard to google... I haven't found an example in 
the test file coming with LPeg either.

--
Philippe Lhoste
--  (near) Paris -- France
--  http://Phi.Lho.free.fr
--  http://PhiLho.deviantART.com
--  --  --  --  --  --  --  --  --  --  --  --  --  --