Yes, but the solution requires editing the mod. I think I posted my solution earlier in the thread. I will go back and review my adjustments to this mod that provide a truly hidden message capability. As distributed the mod is working as designed, which seems to be geared more towards quiz/testing with hints and such embedded. Nothing wrong with that at all, it just didn't fit my application.
More info: I went back and looked through my code to find where I addressed this. I also ran a few tests to confirm my memory. In my case I only have SHOWTOGROUPS enabled, and I have the HIDE tag mapped to SHOWTOGROUPS. The HIDE tag has no paramaters, which when mapped to SHOWTOGROUPS causes the strip_bbcode function to fail in replacing the text. to fix this I added a line of code containing the same regex found in the HIDE-POSTS tag. A note of explanation - the SHOWTOGROUPS tag will default to the groups configuration in the control panel unless specific parameters are entered.
In includes/vS_HHR_Engine.php find:
PHP Code:
$message = preg_replace("/\[(" . $this->tags['SHOWTOGROUPS'] . ")=("|\"|'|)([0-9,]+)\\2\](.*)\[\/\\1\]/siU", $replacement, $message);
Add above that line:
PHP Code:
$message = preg_replace("/\[(" . $this->tags['SHOWTOGROUPS'] . ")\](.*)\[\/\\1\]/siU", $replacement, $message);
This will allow the system to recognize and properly process the SHOWTOGROUPS tag without any additional parameters. If you are using another tag and the hidden text isn't being stripped, then you need to look in the strip_bbcode function to see what is expected to happen.
On the other hand, before you go to a lot of work chasing all this down, make sure you are testing the quoted reply from a usergroup that doesn't have permissions to see the hidden text in the first place!

I'm only saying this because I've made that error myself...