[Xy-pic] A possible bug in labels for the arrow extension? (fwd)

[Ben Whale]

Hi everyone,
  So here is the troublesome xy-pic code.
\ar[ldd]|!{[lld];[rd]}{\quad} doesn't insert \quad wher I want it to,
however, \ar[ldd]|!{[lld];[rd]}{d \quad d} will put the \quad in the right
place (along with the unwanted characters).  What's going on here?

The full code is

\xymatrix@!R@!C{
   &&&&& {m'}\ar@{=}[rrr]\ar[ldd] &&& m'\ar@{=}[ddd]\DW[ldd]\UP[ldd]\\
   \\
   & k \DW[rrr]\UP[rrr] &&& m'\oplus p \DW[rrr]\UP[rrr]\ar[ddl]
                        &&& m \ar@{=}[ddd]\DW[ldd]\UP[ldd]\\
   &&&&&{m'}\ar@{=}'[u][uuu]\ar[ldd]|!{[lld];[rd]}{ \quad  }
         &&&m'\UP[ldd]\DW[ldd]\ar@{=}'[l][lll]|!{[uuu];[lld]}{\quad}  \\
   k \ar@{=}[uur]\ar[rrr] &&& p \ar[rrr] &&& m'' \ar@{=}[ddd]\\
   &\tilde{k}\ar'[u][uuu]\DW@{-}[rr]\UP@{-}[rr]

&&\DW[r]\UP[r]&m'\oplus\tilde{p}\DW@{-}[rr]\UP@{-}[rr]\ar'[u][uuu]\ar[ldd]
         &&\DW[r]\UP[r]&m \UP[ldd]\DW[ldd] \\
   \\
   \tilde{k}\ar@{=}[ruu]\ar[uuu]\ar[rrr]&&&\tilde{p}\ar[uuu]\ar[rrr] &&&
m''\\
   & q\ar@{=}[ldd]\ar'[u][uuu]&&&
q\ar@{=}[ldd]\ar'[u][uuu]\ar@{=}'[l][lll]\\
   \\
   q\ar[uuu]\ar@{=}[rrr] &&& q\ar[uuu]\\
  }

But why would you want to read that, its far to messy!!

cheers,
Ben Whale