Had problems with custombuild compiling icu in combination of httpd 2.2.15 + PHP 5.3.2
Following fixed the problem:
rm -f /usr/local/directadmin/custombuild/icu4c-4_6_1-src.tgz
rm -rf /usr/local/directadmin/custombuild/icu
./build update
# Download needed file
./build icu
# Compile
# Continue to build all programs with default answers
./build clean
./build all d