Static Library problem(json-framework) after upgrade to Xcode 3.2.3

Question

Hi,

In one of my projects, I am using the json-framework library. Everything was working fine, but after upgrading to Xcode 3.2.3, where the oldest simulator available is 3.2 I get the following compilation warning and subsequent (I'm pretty sure related) errors:

warning: in /Users/yahuie/Desktop/pinnionRepo/Tabs copy/Classes/JSON/iphoneos.sdk/usr/local/lib/libjson.a, file was built for unsupported file format which is not the architecture being linked (i386)

 -[NSCFString JSONValue]: unrecognized selector sent to instance 0x6050a002010-07-29 15:11:34.520 Tabs[1420:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSCFString JSONValue]: unrecognized selector sent to instance 0x6050a00'

I have included the source files in my project. Do I need to rebuild the libjson.a file? How?