Whats up with spirit light?

Hello; atm the moment i am running a spirit ritualist build; but have tried to make it a bit more versatile by adding some resto skills.

I have communing at 15; restoration at 10; and spawning at 9.

I take...

Mend Body and Soul
Spirit Light
Boon of Creation
Shelter
Displacement
Union
Shadowsong
Flesh of my flesh.

NB; I have not gone far enough to cap ritual lord yet. Also, I quite like shadowsong anyway, but it is mostly included so that there is a longer lasting spirit in play to gain more reliability in the condition removal benefits from mend body and soul; and to avoid the 10% hp penalty of Spirit Light. I anticipate that once i have ritual lord; it will make shadowsong unnecessary.

Anyway; my main point here is with spirit light. It appears to be bugged in some way. Firstly; on some occasions it just doesn't work; ie it doesn't heal a thing. Secondly; on other occasions it doesn't heal for as much as it should. At 10 resto it should heal for about 110; but quite often i see it heal for +87 +93 or whatever.

Has anyone else experienced this problem? Is it a bug or am I just being dense (which is often the case:P)? The only thing I could think of was that there is some sort of healing debuf in play.

Er... I do believe there have been other threads on this topic. Currently, the consensus belief is that it is a bugged elite. But dont quote me on it.

Apolgies; i did search for other threads first; must have missed it; i will look again now; sorry.

Edit: as is so often the case; search page now not working