Hi all.
I have some strange problems with my regexp. Here is a code describing the problem (б - the second letter in the Russian alphabet, Б - same letter in uppercase, а - the first letter in the alphabet, я - the last letter in the alphabet):

use utf8;
print 'бБ' =~ /^[а-я]+$/i ? 'regexp ok' : 'regexp fail', "\n";
__END__
regexp ok

Ok, expected result

use utf8;
print 'Бб' =~ /^[а-я]+$/i ? 'regexp ok' : 'regexp fail', "\n";
__END__
regexp fail

Not ok, very unexpected fail. Only the sequence of letters in the tested string was changed. Why fail?

use utf8;
print 'Бб' =~ /^[\x{430}-\x{44f}]+$/i ? 'regexp ok' : 'regexp fail', "\n";
__END__
regexp ok

Ok, \x{...} notation helps to avoid this strange problem.
So, WTF? How, to avoid problem without converting letters in regexp to \x{...} notation?
Thanks ;)

__DATA__
$uname
Linux
$perl -v
This is perl, v5.10.1 (*) built for x86_64-linux-gnu-thread-multi
$locale 
LANG=ru_RU.UTF-8
LANGUAGE=
LC_CTYPE="ru_RU.UTF-8"
LC_NUMERIC="ru_RU.UTF-8"
LC_TIME="ru_RU.UTF-8"
LC_COLLATE="ru_RU.UTF-8"
LC_MONETARY="ru_RU.UTF-8"
LC_MESSAGES="ru_RU.UTF-8"
LC_PAPER="ru_RU.UTF-8"
LC_NAME="ru_RU.UTF-8"
LC_ADDRESS="ru_RU.UTF-8"
LC_TELEPHONE="ru_RU.UTF-8"
LC_MEASUREMENT="ru_RU.UTF-8"
LC_IDENTIFICATION="ru_RU.UTF-8"
LC_ALL=

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In reply to Regular Expressions, ignore case and unicode by OlegG

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