Lack of diplomacy turn the AI against ut MUCH easier....

Again, check the Foreign Policy window, it shows the factors that influence how the AI think of you. It may be your ethical alignment, it may be that you have a weak military or ecomony and they think you'll be easy prey, it may be that they don't like your transports hanging around, they may not like how much of the galaxy or their territory your influence is spread across, etc.

Shall i consider this i bug?

Nope, you should consider it a lesson in the importance of diplomacy.

Your diplomacy score is partly a measure of how well you understand and can relate to other cultures, or, to put it another way, how well you can talk to someone very different from you without pissing them off. If you have a low diplomacy score, you are more likely to make a relations-damaging faux pas, like eating the Drengin's ceremonial stinkweed at the banquet thinking it's a salad. The Drengin have been known to lay waste for far less.

LOL hehe but me dont lika diplo... me like big guns and explosions...

Okey my empires are often vast, though im not in anothers territory if im not gonna invade. I never have weak military (though only defence until im gonna invade), My influence if often over their planets as well i guess thats the case... gah its to bad there arnt "real" borders in this game

I like the infuence borders. It would be kind of weird to have real borders in space because it is so huge, and it seems weird to actually claim a sections of space. Atleast that is how I feel about it.

HeHeHe! I too am a gun wielding conqueror, but i know well the importance of diplomacy. Especially early in the game. Notice that when you meet the first AI, they all seems to be pretty far advanced in tek compared to you. Also, most are much better than you at diplo so exchanging tek is costly.

But don't worry! Research something they don't have and start SELLING it for cash. This give you more time at 100% spending rate which in turn makes you outproduce and outresearch the AI in the long term. In my games, i give away for cash most of my first research. Sometimes it pains me to give a good research away, but it is always worth it. And doing so will rise your standing a lot with other AI. And they won't attack you because you are their friend.

You can make a lot of cash with this, especially the minor race who don't know what to do with their cash. When you sell a tek, try to sell it to everyone in the same turn, because if you don't do it, there is a good chance that the ai will. Especially early in the game where everyone is chummy chummy. Later in the game, i've found that the AI is far more reluctant to give away all the teks. Especially to their ennemies...

If you want the real reason, check out the foregin relations tab. Gives a full breakdown of why they hate you. Trade is good not for the money, but for the diplomacy advantage it affords.

More diplomacy= cheaper everything.

No matter your path to victory, high diplomacy (through techs race bonuses are not really necessary) is almost a must on maps with 4 or more opponents; not only will you be attacked less but you can buy up techs and mining resources (personally once my economy is in full swing I buy every single mining starbase).

Without racial diplo bonuses and if your an evil civ you can expect to go through a "rough patch" where everyone hates you, but diplo techs in conjunction with killing those who really don't like you can slowly turn your overall standing around.

By the sound of the OP however your problem is a low military rating and not a diplomacy problem, the AI usually compares your empire to a bug if they have a higher military score.