www::search

Hi all,
Problems on using www::search::yahoo and www::search::excite.
When I use www::search::yahoo, it always prompt me with this error, "Parsing
of undecoded UTF-8 will give garbage when decoding entities at
..../lib/www/Search.pm line 1744."

When i use www::search::excite, it prompts me with "LWP::RobotUA from
address required at .../lib/www/Search.pm line 1144"

How can I solve these problems?

Thanks