srv01 ~ # emerge -av phpmyadmin

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild  N    ] app-admin/webapp-config-1.50.16-r1  102 kB
[ebuild  N    ] virtual/httpd-php-5.3  0 kB
[ebuild  N    ] app-text/recode-3.6_p16  USE="nls" 2,021 kB
[ebuild  N    ] net-libs/c-client-2007e  USE="pam ssl -kolab" 2,725 kB
[ebuild  N    ] virtual/httpd-cgi-0  0 kB
[ebuild   R   ] dev-lang/php-5.3.3-r1  USE="apache2* berkdb bzip2 calendar* cgi cjk* cli crypt ctype curl* curlwrappers* enchant* exif* fileinfo filter flatfile* ftp* gd gdbm hash iconv imap* intl* ipv6 json kerberos mysql* mysqli* nls phar posix readline recode* session sharedext* simplexml snmp soap* sockets* spell sqlite sqlite3 ssl threads tidy tokenizer truetype unicode xml xmlreader xmlwriter zip zlib -adabas -bcmath -birdstep -cdb -concurrentmodphp -db2 -dbmaker -debug -doc -embed -empress -empress-bcs -esoob -firebird -fpm -frontbase -gd-external -gmp -inifile -interbase -iodbc -kolab -ldap -ldap-sasl -libedit -mssql -mysqlnd -oci8 -oci8-instant-client -odbc -pcntl -pdo -pic -postgres -qdbm -sapdb -sharedmem -solid -suhosin -sybase-ct -sysvipc -wddx -xmlrpc -xpm -xsl" 0 kB
[ebuild  N    ] dev-db/phpmyadmin-3.3.7  USE="-vhosts" 3,582 kB

Total: 7 packages (6 new, 1 reinstall), Size of downloads: 8,428 kB

!!! Multiple package instances within a single package slot have been pulled
!!! into the dependency graph, resulting in a slot conflict:

dev-lang/php:5

  ('installed', '/', 'dev-lang/php-5.3.3-r1', 'nomerge') pulled in by
    =dev-lang/php-5.3.3-r1[-imap,-mysql,-mysqli] required by ('ebuild', '/', 'dev-lang/php-5.3.3-r1', 'merge')
    (and 8 more)

  ('ebuild', '/', 'dev-lang/php-5.3.3-r1', 'merge') pulled in by
    dev-lang/php[mysqli] required by ('ebuild', '/', 'dev-db/phpmyadmin-3.3.7', 'merge')
    (and 8 more)


It may be possible to solve this problem by using package.mask to
prevent one of those packages from being selected. However, it is also
possible that conflicting dependencies exist such that they are
impossible to satisfy simultaneously. If such a conflict exists in the
dependencies of two different packages, then those packages can not be
installed simultaneously. You may want to try a larger value of the
--backtrack option, such as --backtrack=30, in order to see if that will
solve this conflict automatically.