[collections] Problems compiling w/gentoo

[tenspd137 .]

Hi all -

I am using gentoo to install common-collections-3.2.1.  I keep getting
errors like:

Buildfile:
/var/tmp/portage/dev-java/commons-collections-3.2.1/work/commons-collections-3.2.1-src/build.xml

init:
     [echo] -------- commons-collections 3.2.1 --------

prepare:
    [mkdir] Created dir:
/var/tmp/portage/dev-java/commons-collections-3.2.1/work/commons-collections-3.2.1-src/build

compile:
    [mkdir] Created dir:
/var/tmp/portage/dev-java/commons-collections-3.2.1/work/commons-collections-3.2.1-src/build/classes
    [javac] Compiling 273 source files to
/var/tmp/portage/dev-java/commons-collections-3.2.1/work/commons-collections-3.2.1-src/build/classes
    [javac]
/var/tmp/portage/dev-java/commons-collections-3.2.1/work/commons-collections-3.2.1-src/src/java/org/apache/commons/collections/MultiHashMap.java:334:
error: remove(Object,Object) in MultiHashMap cannot implement
remove(Object,Object) in Map
    [javac]     public Object remove(Object key, Object item) {
    [javac]                   ^
    [javac]   return type Object is not compatible with boolean
    [javac]
/var/tmp/portage/dev-java/commons-collections-3.2.1/work/commons-collections-3.2.1-src/src/java/org/apache/commons/collections/MultiMap.java:69:
error: remove(Object,Object) in MultiMap clashes with remove(Object,Object)
in Map
    [javac]     public Object remove(Object key, Object item);
    [javac]                   ^
    [javac]   return type Object is not compatible with boolean
    [javac]
/var/tmp/portage/dev-java/commons-collections-3.2.1/work/commons-collections-3.2.1-src/src/java/org/apache/commons/collections/map/MultiKeyMap.java:200:
error: remove(Object,Object) in MultiKeyMap cannot implement
remove(Object,Object) in Map
    [javac]     public Object remove(Object key1, Object key2) {
    [javac]                   ^
    [javac]   return type Object is not compatible with boolean
    [javac]
/var/tmp/portage/dev-java/commons-collections-3.2.1/work/commons-collections-3.2.1-src/src/java/org/apache/commons/collections/map/MultiValueMap.java:156:
error: remove(Object,Object) in MultiValueMap cannot implement
remove(Object,Object) in Map
    [javac]     public Object remove(Object key, Object value) {
    [javac]                   ^
    [javac]   return type Object is not compatible with boolean
    [javac] 4 errors

Any thoughts why this might be occurring?

Thanks!

-Collin