Mystcraft Portals misbehaving

[cloj63]

I did a round shaped portal 2 days ago, working well.
But I made some modification on buildings around and when I wanted to change the link book of the portal, I could not recreate another one...
It was working well before I removed the old link book, but now I cannot seem to make it work. Tried doing the same exact portal shape at another place and it was working.
Is there some block that could enter in conflict with the mystcraft portal?

I can't figure out what is going on....

 

[ApSciLiara]

To clarify, wrath lamps use invisible blocks to provide their light.
Mystcraft doesn't like anything being inside the portal frames when you activate it.
If you activate the portal THEN place down the wrath lamp, it should work.

 

[cloj63]

Wow, thanks.
Now that you mention it, I did place the wrath lamps after making the portal.
Wonderful!