authentication failure on paypal classic api

paypalcall.rb

require 'paypal-sdk-adaptivepayments'

#set the api credentials
PayPal::SDK.configure(
  :mode      => "live",
  :app_id    => "APP-8TA367141A153745A",
  :username  => "arun_api1.wakemate.com",
  :password  => #HIDDEN,
  :signature => "A5apZv808uLSmMYKU32Uz0S3VglPA4gSn10Qcf3-iJjfWBq-bMpQxEh8y")

@api = PayPal::SDK::AdaptivePayments::API.new

# First I tried a convert currency request

#build api request
@convert_currency = @api.build_convert_currency({
  :baseAmountList => {
    :currency => [{
      :code => "USD",
      :amount => 2.0 }] },
  :convertToCurrencyList => {
    :currencyCode => ["GBP"] } })

#make api request
@convert_currency_response = @api.convert_currency(@convert_currency)

#ERROR RESPONSE FROM PAYPAL SERVERS
 => #<PayPal::SDK::AdaptivePayments::DataTypes::ConvertCurrencyResponse:0x007fc299177150 @responseEnvelope=#<PayPal::SDK::AdaptivePayments::DataTypes::ResponseEnvelope:0x007fc299176fe8 @timestamp=Mon, 09 Dec 2013 13:37:06 -0800, @ack="Failure", @correlationId="a978929c5cb5c", @build="7935900">, @error=[#<PayPal::SDK::AdaptivePayments::DataTypes::ErrorData:0x007fc2991762f0 @errorId=520003, @domain="PLATFORM", @subdomain="Application", @severity="Error", @category="Application", @message="Authentication failed. API credentials are incorrect.">]>
@convert_currency_response.error
 => [#<PayPal::SDK::AdaptivePayments::DataTypes::ErrorData:0x007fc2991762f0 @errorId=520003, @domain="PLATFORM", @subdomain="Application", @severity="Error", @category="Application", @message="Authentication failed. API credentials are incorrect.">] 
@convert_currency_response.error[0].errorId
=> 520003
@convert_currency_response.error[0].message
=> "Authentication failed. API credentials are incorrect."


#then I tried a simple payments request found in the SDK README on the github page

# Build request object
@pay = @api.build_pay({
  :actionType => "PAY",
  :cancelUrl => "http://localhost:3000/samples/adaptive_payments/pay",
  :currencyCode => "USD",
  :feesPayer => "SENDER",
  :ipnNotificationUrl => "http://localhost:3000/samples/adaptive_payments/ipn_notify",
  :receiverList => {
    :receiver => [{
      :amount => 1.0,
      :email => "platfo_1255612361_per@gmail.com" }] },
  :returnUrl => "http://localhost:3000/samples/adaptive_payments/pay" })

# Make API call & get response
@response = @api.pay(@pay)

#paypal response
 => #<PayPal::SDK::AdaptivePayments::DataTypes::PayResponse:0x007fc294972878 @responseEnvelope=#<PayPal::SDK::AdaptivePayments::DataTypes::ResponseEnvelope:0x007fc2949727b0 @timestamp=Mon, 09 Dec 2013 13:36:40 -0800, @ack="Failure", @correlationId="e0af0a32fbe87", @build="7935900">, @error=[#<PayPal::SDK::AdaptivePayments::DataTypes::ErrorData:0x007fc295f909c0 @errorId=520003, @domain="PLATFORM", @subdomain="Application", @severity="Error", @category="Application", @message="Authentication failed. API credentials are incorrect.">]>