Hi exchange admins!

With SP2 for Exchange 2007, MS reintroduced server backup integration of exchange also on server 2008 (SP2, too). So...this should now all be so easy (see http://msexchangeteam.com/archive/2009/05/13/451311.aspx).
But it ain't for me.  This question adresses those who actually use this integration.

I used the wizard of server backup to configure a backup to another local disk (no, this is not the location we plan to keep the backup for good). The exchange aware backup starts alright, backs up c: (system) without problems, starts with d: (exchange db), moves to 99,9% and ... fails.

Status: Failed
The parameter is incorrect.
However, the disk backup is there with the expected size, although the backup disk has to be mounted (given a drive letter) first. But, it is no good for recovery.

Wonderful. What parameter, the wizard set up the backup parameters...
If I look at the task that gets created, its:
wbadmin.exe start backup -templateId:{dca8edf3-f40c-4ba6-bc91-6fa50dc25cf9}

Questions
Q1: Does anyone of you succesfully use this? What's your config/disk setup?
Q2: how can I make wbadmin a little more verbose?
Q3: what does that templateID imply, can I get more info on parameters?
Q4: what could go wrong at 99,9%?

I will divide points based on answering the 4 questions, however, feedback, comments and questions are welcome as long as you are using this method yourself.
Ah, by the way: the "best practices analyzer" is more than happy with our setup, he just would like to see more backups succeeding ;)