What is your power rating? It may be a product of making a more aggressive AI, and you not having a large enough power rating vs. other AI people.
The AI is programmed, if it is facing immediate revolutionary threat, and it can't do anything else, to desperately launch an unprovoked attack against a civilisation which is weak. Capturing thier cities will SIGNIFICANTLY (IE. give a 300 stability boost in each city) ease the pressure... even stop it entirely!
The AI, in these wars, however, is less inclined to let a weak albiet friendly civ live (IE. Diplomacy, although it helps, it helps less than regular wars, where the aim is conquest, not survival). As a direct result of this, the AI in revolutions is more aggressive. The AI is also more aggressive (slightly) because of the Better AI patch.
If you have a low strength rating, then you WILL be dogpiled on. It is something I learned in the third game I played (Playing as the Khmer, I have NOT been declared war on by an AI yet, solely because I built a GIANT stack of spears to defeat the russians, which made my strength ratio fully 3 times the normal strength I play with at a comparable time). However, if you build many many troops, you will be able to both defend against the few wars which are sent your way, and you will be able to stop those wars before they even start! (The AI won't declare on a stronger opponent, if they are nearing revolutionary collapse... that is just suicide!)
I think turning of Revolutions should help ... however it also kills the best part of RoM IMO.
If this doesn't help, and you are getting dogpiled with good relations AND a good strength ratio, please provide a save AND your log files (In your Rise of Mankind MOD folder, the one where you installed AND into. It is called "A New Dawn.log"), as that is almost certainly a bug. Or the AP.
Oh, and also, the order of events for ALL war declarations (even in Beyond the Sword) is:
*Do I like them? If no, continue
*Build army
* Send army
* Declare war
By the sounds of it, you see thier army bordering your nation, and you try and bribe them to friendly. Unfortunatly, that time has come and gone, my friend... you needed to bribe them BEFORE they built thier army, and BEFORE they sent thier army. Seriously, would YOU waste thousands upon thousands of hammers on a military, and then waste hundreds and thousands of GPT on managing this larger army AND the 'army outside of your borders' increased GPT penalty AND risk weaker defences in your core cities, only for you to suddenly get 100 Gold and a free tech, and turn around, cancelling your plans?? No you wouldn't. And neither will the AI.