Import XML WXR errors – Wrong Parameter Count

I get 2 error messages when I try to import posts, categories, etc, from another WP installation.

The first says:
Warning: Wrong parameter count for log() in
../wp-admin/includes/template.php
on line 583

The second says:
Import WordPress
The uploaded file could not be moved to
../wp-content/uploads/2007/11.

The first error message points to the template.php and within it, to a line that seems to be reporting the size of files I can upload. Does it mean that there’s a space issue with files and file storage?

here’s the code;
the 3rd line, beginning with $log, is where the message points:

function wp_convert_bytes_to_hr( $bytes ) {
	$units = array( 0 => 'B', 1 => 'kB', 2 => 'MB', 3 => 'GB' );
	$log = log( $bytes, 1024 );
	$power = (int) $log;
	$size = pow(1024, $log - $power);
	return $size . $units[$power];
}

What do I need to do?

Separate Problem: A few days back I registered w another username but the confirmation email hasn’t arrived. What do I do?