Less is more !!!

After one year of MFI I have come to the conclusion that "less is more" in terms of analysis of the stocks I buy and own. Well, not 100% less (or complete faith) - meaning no self research, but anything more than 5 minutes per stock is not a good idea for myself.
There is always a reason that a stock is on the MFI list -- earnings hike is just a one-time thing; future earnings outlook is dreadful because industry in total decline (check business - forgot the name - did not buy the stock); oil field is somewhere in Africa and political problems (EGY); copper prices are only up temporarily (FCX); all business is with one customer who may choose to take a hike (my nightmare with Portalplayer) -- there is always a reason and you should be able to see the reason within 5 minutes. Usually there is a break in the chart and all you have to do is check for the news around that time.
Once I am past the 5 minute mark and especially if I don't see the obvious reason - I am in trouble, because I start "liking" the stock more than I should. I just could not understand why Portalplayer was on the list with being part of the most successful consumer product this decade (IPOD) -- so I bought more stock "outside" of my MFI portfolio - BIG mistake.
The almost made the same mistake with Grubb-Ellis - the commercial real estate company - I can't figure out why the stock is so low. There are buy-outs in the industry - the stock is valued very low and Grubb-Ellis has a good name. I can't quite figure out the ownership situation and classes of stocks they have sold - which I think is the reason the stock is not doing very well. But I went beyond my 5 minutes and spent a lot of time on this and it is just not very useful.
Blind faith - or picking at total random has not worked either. I picked my May portfolio of 7 stocks at random and they are not doing so well (about 2% gain vs 15 for indexes). There were 2 stocks in particular, I almost knew would be dogs right after I bought them - National Dentex and Toptanker.
So in the future, I am going to stick to the 5 minute rule and finding the reason, each stock is on the MFI - but that's just for me.