I have 3 parsers and they are come out with different numbers on the same fight.  This seems to be ok but you can never tell since they all read the crappy logs different.

Fujitsu,

I downloaded that parser and checked out one of my old logs that I had, and between that and the other parser the only real major differences that I can see in the 2 is the DPS & Duration.

Just looking at 1 fight (should probably looked at a different fight cos some of the others are closer than this one):
In VGLP it says:
Duration: 18s
Dmg: 7113
DPS: 395

In YAVLP same fight:
Duration: 62s
Dmg: 9028
DPS: 145

Now I manually looked at the log itself and the fight did only go for 18s (going by the time stamps in the log) and the first one seemed to be closer to right then the second.

I did read in the instruction that you need to have everything turned on in the window that you are parsing so it forces update more often, I'm just wondering if by me not having everything turned on if this has wrecked it somehow.

I will test either later tonight or sometime tomorrow, with everything turned on and see what the difference is, if there is any.

Edit:

I've just been checking over some of the other fight and having a bit more of a look around. Finding out how to kinda look at each fight, I found that you can look at the chart/graph of that fight.

Now here is where I think something is going wrong, the data might say I did X dmg over X duration, but when I look at the Graph it says I did X dmg over Y duration ( Y duration being closer to what the other parser & the log is saying).

So not really sure what I'm doing wrong or if its just somehow not reading the logs right... But like I said will test it more later.

I mostly used the one you linked Fujitsu for parsing during raids and stuff.  I like that it is updated and seems to be the most accurate from what I can tell.