You know, after I posted the message I thought about it and decided to go ahead with 4. Sometimes you just need to write things down to see the answer clearly.
But, it is the mysqli extentions which I am concerned with because when PHP5 comes out I am going to have to recode for the additional transaction functions.
So 4 offers everthing 4.1 does, it is only the mysqli functions that I am concerned with. But most of those equivelents can be handled with raw sql code (mysqli_Commit, mysqli_Rollbad)
Thanks for your opinion, I was still kicking the IDEA around and wandering if I was making a mistake and hearing anothers opinion fortifies mine.
THanks