[TxMt] Snippet Braces Matching Problem

[Phil Molyneux]

I have the following snippet where the tab $1 is intended to match the 
whole string (to be used in LaTeX)

${1:\NMsubject{\textbf{${2:Subject}}}}

However the tab $1 does not match the last two braces - I suspect this 
is an issue with the LaTeX and TextMate use of braces.

The snippet below works as expected (but would be no use in LaTeX

${3:someText|someMoreText|${4:Subject}||}

Is there some way to get $1 above to match to the last brace ?

Phil