i know exactly which multi-vitamin you're speaking of, because i looked at the same thing and, unlike your wise decision, passed on it, laughing all the way down the aisle. boy, will my cynicism ever cease? well, needless to say i'm on them now! hah! okay so . . .
lycopene!!!
i think that might be somewhat of an indicator to why it's working. lycopene is something they added to this particular multi-vitamin for the 'prostate health' the label promotes.
as far as i've read,

"In the body, lycopene is deposited in the liver, lungs, prostate gland, colon and skin. Its concentration in body tissues tends to be higher than all other carotenoids. Some organs, such as the testes and adrenal glands, store higher levels of lycopene than do other organs or tissues. . .
. . . Dietary consumption of lycopene (mostly from tomato products) has been associated with a lowered risk of prostate cancer. Men with higher levels of lycopene in their blood had statistically significant lower rates of cancer than did men with lower blood levels of lycopene. Studies have also shown that men who eat more lycopene-rich foods have less heart disease."

, i've become more interested in this idea. has anyone experimented with any larger doses of this vitamin / anti-oxidant / thing-o (technical term)?
perhaps you cleared out your epididimys unknowingly with the fenugreek and then helped repair the damage done to the tissue due to inflammation and infection with lycopene? maybe you just didn't need the fenugreek and repaired via lycopene? hell, these are stabs in the dark with a blindfold and earmuffs on, but something seems to be working here . . .