If you are running ColdFusion 7 & IIS6 you may be experiencing a "connection failure" message when trying to connect to the PayPal API. A Verisign Root SSL update September 2009 caused the problem. ColdFusion 8 users were unaffected. While reported to PayPal users prior to the update, CF 7 users may have been caught unaware as dealing with SSL in ColdFusion is something generally taken for granted. 

To fix the issue:

ColdFusion 7 Standard

1) Download the root certificates from the link below and copy the "Class 3 Public Primary Certification Authority - G2.cer" certificate to the C:\ drive. Rename to "vs-g2-import.cer".

2)  At a Command Prompt type the following three commands in sequence. Replace your drive letters accordingly and remove the quotes.

"E:"

"CD E:\CFusionMX7\runtime\jre\bin"

"keytool.exe -import -keystore E:\CFusionMX7\runtime\jre\lib\security\cacerts -storepass changeit -noprompt -trustcacerts -file c:\vs-g2-import.cer -alias vs-g2-import-09-09-30"

3) Restart all instanced of ColdFusion

ColdFusion 7 Enterprise 

I modified the instructions slightly to reflect our drive setup and the fact it's the enterprise version.

1) Download the root certificates from the link below and copy the "Class 3 Public Primary Certification Authority - G2.cer" certificate to the C:\ drive. Rename to "vs-g2-import.cer".

2)  At a Command Prompt type the following three commands in sequence. Replace your drive letters accordingly andremove the quotes

"E:"

"CD E:\jrun4\jre\bin\"

"keytool.exe -import -keystore E:\jrun4\jre\lib\security\cacerts -storepass changeit -noprompt -trustcacerts -file c:\vs-g2-import.cer -alias vs-g2-import-09-09-30"

3) Restart all instanced of ColdFusion

Link to Root Certs:

https://ppmts.custhelp.com/cgi-bin/ppdts.cfg/php/enduser/std_adp.php?p_faqid=800

ColdFusion Solution First Reported Here:

http://developer.paypal-portal.com/pdn/board/message?board.id=nvp&message.id=5571