剧情是这样，我的app要使用两个library，如：LibraryA，LibraryB。这两个库又都需要support.v4.jar。
由于加载的时间不同，所以两个support.v4.jar不同，出错的提示如下：
[2012-09-28 16:37:22 - ] Found 3 versions of android-support-v4.jar in the dependency list,
[2012-09-28 16:37:22 - ] but not all the versions are identical (check is based on SHA-1 only at this time).
[2012-09-28 16:37:22 - ] All versions of the libraries must be the same at this time.
[2012-09-28 16:37:22 - ] Versions found are:
[2012-09-28 16:37:22 - ] Path: /home/zkw/workspace/MyApp/libs/android-support-v4.jar
[2012-09-28 16:37:22 - ] Length: 247894
[2012-09-28 16:37:22 - ] SHA-1: 7329492e76650ee661f6af7704b0c79151d8e1ef
[2012-09-28 16:37:22 - ] Path: /home/zkw/workspace/LibraryB/library/libs/android-support-v4.jar
[2012-09-28 16:37:22 - ] Length: 271754
[2012-09-28 16:37:22 - ] SHA-1: 53307dc2bd2b69fd5533458ee11885f55807de4b
[2012-09-28 16:37:22 - ] Path: /home/zkw/workspace/LibraryA/libs/android-support-v4.jar
[2012-09-28 16:37:22 - ] Length: 247894
[2012-09-28 16:37:22 - ] SHA-1: 7329492e76650ee661f6af7704b0c79151d8e1ef
[2012-09-28 16:37:22 - ] Jar mismatch! Fix your dependencies
从提示中可以知道，这三个support-v4.jar不同，所以会发生冲突，解决方法就是，把其中某个不同的，比如LibraryB/library/libs中的support-v4.jar文件删掉，然后刷新这个包，让他重新生成，然后就OK了