I've always found C++'s "trend" of handling normal or non-exceptional system errors with exceptions lackluster (and I'm being charitable). Overall trimming things down to (basically) passing around a couple integers and telling the user to check their manual is much better, much less error prone, and much more efficient and deterministic.
I have no problem with localizing error messages... I just think an error handler is the absolutelest wrong place to do it. Localize it in the manual. Appendix C page 3, "Spanish / Español". Error routines should print machine-readable information. A couple numbers. Maybe a smiley (or, given the context, frownley).