translation doesn't work with second field name in "matches" validation rule

[eluser]liviu_holhos[/eluser]
It's from a beta 1.7.3, but at this time I can't remember where I got it from, sorry.
I hardly found it last month on github somewhere, I'll leave the document publicly available for anyone having this problem.

Later edit: I think it's from cbosuna's github: http://github.com/cbosuna/codeigniter