Empty $template variable in Mail.php

[GUNSO]

Hi guys
I'm upgrading from 1.0 to 1.3 and everything looks good except this error here when placing order:
Error: mail parameters are corrupted

The order is placed but no email sent out..I have debug it and found out that $template variable on Mail.php is empty.

Any idea what might cause that? I'm using the bankwire payment module.
Where is it calling to Mail.php so i can try to find out why this variable is empty?

regards
Gunnar