try enabling this option.
@item target=<target>
-Specifies a particular SDK target, when the source doesn't. This is
-likely to cause the whole build.xml to be rewritten, which is fine if
-it's a 'standard' android file or doesn't already exist, but not a
-good idea if it's heavily customised.
+Specifies a particular SDK target for compilation, overriding the
+project.properties of the app and possibly sub-projects. Note that this does
+not change the target SDK in the AndroidManifest.xml — the level of features
+that can be included in the build. This is likely to cause the whole build.xml
+to be rewritten, which is fine if it's a 'standard' android file or doesn't
+already exist, but not a good idea if it's heavily customised. If you get an
+error about invalid target, first try @code{init=rm -rf bin/}; otherwise this
+parameter should do the trick.
@item update=xxx
By default, 'android update project' is used to generate or update the