[TYPO3] direct_mail_subscription - Links and Thunderbird

[PEF]

Hi!

When sending a confirmation mail to the subscriber, the link is only 
partly prepared - the part from the first [ and to the end of line is 
not included:

This part is marked as a link:
http://mydomain/index.php?id=74&type=0&1=1&cmd=setfixed&sFK=approve&rU=50&fD

This part is not:
[_FIELDLIST]=uid&fD[hidden]=0&aC=58f39fcd

If I change the [ and ] to &#91 and &#93 it works all right.

Is there a smart way of changing these permanently or do I have to 
change the php-code for the extension?

It must be a general problem considering that many extensions use 
typo3-functions that generates links this way.

Regards
Peter Falk