Years of confusion

[Rex]

I bought my brother a keg tap from a local dealer in Sacramento, Ca in July of 2004. I had a buddy of mine pick it up for me from a shop I was/am unfamiliar with. It was assembled using a MicroMatic black handled keg coupler, a chrome pump, and hose with valve at the end. I paid over $100.00 for it and it hasn't worked for sh*t since the day it was bought. My brother recently left for Africa and I happened upon the tap today and began to wonder what the hell was wrong with it.
As MicroMatic is the only name that I can find on the tap, I sought it's website; as I looked at pictures of MicroMatic's products on the site, I noticed that the keg couplers shown have the hose/dispensing valve attached at a different point than the one I got.
If my tap is sitting level on a keg, it has the pump coming off at about a 30 angle and the hose coming out of the top. Was this S.O.B. put together wrong?! Most of my confusion stems from the fact that the keg coupler has "GAS IN" on the immediate piece that the pump is screwed onto. Shouldn't this identify that location as the placement of the pump?
This tap has never done more than s-l-o-w-l-y dispense beer from kegs. If it was assembled incorrectly, would it work at all? I recall calling the shop I bought it at and asking if they had any idea what could be causing poor dispensing. The guy I spoke to told me that the dispensing hose could be too long and to shorten it to a foot and a half. I can't remember if it helped or not, but if it did, it wasn't by much.
Again, is it even possible to incorrectly assemble a keg tap, having effectively switching the placement of the pump and the hose? If it is possible, would one be able to pull any beer through it? If none of this makes sense, any ideas on what may cause a brand new keg tap to almost completely fail at dispensing beer? I know this was long and thanks for the help!