Finaly found the solution:
simple as that – php floatval function is dangerous with specific locales
Solution:
add these lines into geotag.php
// help with floatval php function problem with locale
function floatval_safe($value)
{
$value = floatval($value);
$larr = localeconv();
$search = array(
$larr['decimal_point'],
$larr['mon_decimal_point'],
$larr['thousands_sep'],
$larr['mon_thousands_sep'],
//$larr['currency_symbol'],
//$larr['int_curr_symbol']
);
//$replace = array('.', '.', '', '', '', '');
$replace = array('.', '.', '', '');
return str_replace($search, $replace, $value);
}
and replace all occurences of floatval with new function floatval_safe