PayPal checkout currency issue..

hello
I have this issue with my site.. When Cart Default currency is INR (Rs.)

I have selected Bank Transfer for Geo Zone India, and Pay Pal for International Geo Zone.
Payment is working fine, when I login as user with shipping address in India, it shows Bank Transfer as Payment, and when I login as user with USA Address, it shows payment as paypal , on check out..

But !!

During testing, while checking out as USA customer , I got Error from paypal module denominated in WS_Error_XClick_Pref_Foreign_Currency. when I checked paypal is not recognising the currency symbol.
( Paypal is not recognising symbol Rs. INR ) Then I changed the site default currency to USD, checkout worked fine.

Is there any way, currency is selected based on geo zone, ( Eg: India Zone , Rs. INR , All-Others $ USD),
or currency selected automatically via browser, depending on browsing location, Eg: if Location is India , Currency in INR , other locations USD .

If you use my Paypal Itemized Patch, it includes a currency check. If using an unsupported currency like INR, it will convert it to USD by default.

http://www.opencart.com/index.php?route ... ion_id=221

Its somethign I did not include in the PayPal module. It neds to be changed so it will revertt to the default currency if paypal does not accept the selected currency.