Problem in number_helper.rb ?

Hello,

Today I noticed that the number_to_currency helper didn't work anymore
(it just returned the numeric value, without any currency).
I tracked down the error and saw that editing line 89
( number_to_currency method) as follows solved the problem :

Old piece of code :

begin
    format.gsub(/%n/, number_with_precision(number,
      :precision => precision,
      :delimiter => delimiter,
      :separator => separator)
      ).gsub(/%u/, unit)
rescue
    number
end

New one :

begin
    format.gsub(/%n/, number_with_precision(number,
      :precision => precision,
      :delimiter => delimiter,
      :separator => separator).to_s
      ).gsub(/%u/, unit)
rescue
    number
end

Is it an issue with Rails ?

Thanks