Is it the simengine to blame ?

im playing a dynasty right now ... before i am using the default simengine ... we all know that its a fluke so i tried the simengine found in the downloads section ... it went better but the bug is this ... i am using a created player on my dynasty and he is running 1st for MVP the whole season with 32ppg , 8 rpg , 11 apg , 3.5 spg and 2 bpg ... but at the start of the conference semis lebron james ranked fourth in the list but eventually won the MVP with 26,7,8,1 and 2 ...

In a word, yes. The game doesn't always make the smartest decisions when it comes to picking award winners; in fact, it often doesn't. That's probably not one of the worst examples I've seen (although the top rated MVP Candidate usually ends up winning the award it's not always a given) but yes, it's the sim engine/award selection logic. Nothing that can be done about that.

but the default simengine does not encounter such problem ... could you suggest a better simengine for me ?

I guarantee that the same thing will happen from time to time with the default sim engine. As far as I'm aware, that bin file doesn't actually affect the selection of award winners. I'm also pretty sure that yesky's update is the only one that's readily available.

I've said it before but I'll say it again: NBA Live 08 PC is a very sloppy product that's riddled with issues from fatigue not working properly to awful simulated stats. We've done what we can these past few years but when it comes to down to it, there's really only two choices here: put up with the issues or play something else.