Well one needs to understand here what is "Up" and "Down". many people dont really understand that.
If Rs is 50 per 1 USD (also depicted as USD:RS::50:1 or USD/RS - 50:1 or simply USD/RS - 50)
Rs moves to 45 per 1 USD ( Simply USD/RS - 45),
That does mean rupee is falling in its value..!
That means Rupee actually is Appreciating against dollar/Strengthening i.e Initially 50 RS had power to buy 1USD but now even 45 RS can buy 1USD
So if rupee is falling, that means RS is strengthening against weakening USD
Thats how other currencies are also valued
As regard recession,
USD is the only currency right now which people buy(strengthen it) and sell others(make then weak)
when recession fears deepen or there is bad news around (just like Swine flu news few days back)
RS fell to all time weakness of some 51+ just a while back....bcoz of same fears
Other currencies also fell. & USD was strengthened
Now some fears have been allayed and some are saying recession is over, so thats why minor currencies have again started appreciating and so is rupee.
Hope you got the idea at least.