Bridging of 3 WAP54G together using 4 Antennas

Hi all,

I have a question regarding bridging of 3 WAP54G.
We have a central tower on our network where we are trying to bridge the two office blocks together since line of sight between the two office blocks are impossible due to density of trees.
My question as such is I have three WAP54G one on Office Block A one on the Tower and one at Office Block B.
I have been trying to bridge the two office blocks together through the the AP on the Tower. I have an WAP54G Linksys with a 24DBi to Office Block A where there is a WAP54G Linksys with a 24Dbi Antenna.
For Office Block B I have an 18Dbi Antenna Pointing to the Tower where there is an 18 Dbi Antenna. The Antenna selection on the tower is Diversity. At Office Block A its right and at Office Block B its Left.
The Mac Address for Office A and B has been configured onto the AP on the Tower and vice versa.
The problem is when I try to connect Office Block B goes offline.
Any suggestions or recommendations I am struggling to sort it out at this stage and need these offices online as soon as possible.

Been surfing the net trying to get possible reasons but to no avail.

Hope someone can help!
Cheers
CHS007.