Modify currency in community edition


I have the following trouble with the community edition.

I need to use only one currency, but I am not able to change the proprieties of the original US Dollars currency.

When I try to modify any field (name, code or sign), I have the following error message when I save :

[color=#8C8531][font=Tahoma, Arial, Verdana,]Currency exchange rate should be higher than 0.[/font][/color]

How can I change the $ in CHF for example ?

Thank you in advance for your help,

This has been reported and fixed. Go here: