timing belt replacement mileage for '06 Beetle tdi

At what mileage is it recommended to replace the timing belt? Do you need to replace a water pump at the same time?

Thanks

Maintenance schedule

http://pics.tdiclub.com/data/516/2006_All.pdf

TB replacement procedure:
http://pics2.tdiclub.com/pdf/a4timingbelt.pdf

TB kit:
http://www.idparts.com/catalog/product_info.php?products_id=511
http://www.idparts.com/catalog/product_info.php?products_id=1236

Not only that, if you have never had the timing belt changed regardless of mileage, now is the time. I changed mine at 32k because the timing belt was 8 years old (as per one of the outstanding gurus here) so age is also a factor.