I think the old version of the driver must appear earlier in your module path than the new one, so you're still using the version that doesn't support the command.
I just verified for myself that the command is working. I built the Perl client driver, installed with nmake, recorded a simple test with the IDE, exported as Perl, and then ran the test. The screenshot was created successfully. Here's my test for reference (although it doesn't sound like the test is your problem):
use strict;
use warnings;
use Time::HiRes qw(sleep);
use Test::WWW::Selenium;
use Test::More "no_plan";
use Test::Exception;
my $sel = Test::WWW::Selenium->new( host => "localhost",
port => 4040,
browser => "*chrome",
browser_url => "http://www.google.com/" );
$sel->open_ok("/");
$sel->type_ok("q", "yoo");
$sel->click_ok("btnG");
$sel->wait_for_page_to_load_ok("60000");
$sel->capture_entire_page_screenshot_ok("D:\\work\\temp\\yoo.png", "");
Check your @INC. Looks like the new driver was installed under C:\perlapache ... mine was installed under C:\Perl (ActivePerl).
Haw-Bin
