My vessel doesn't stop accelerating

[elsheik]

Hi, first of all, sorry my English.

I had played KSP for a long time, now I just updated to 1.2 and I was fixing the typical "mod mess" that every update causes, so I only left a couple of mods. 

The problem is that whenever I launch a vessel and reaches space (70/80 km) I burn to establish a low orbit but then my vessel doesn't stop accelerating, even in space with engines totally turned off. It's like the Kraken itself is dragging it somewhere into space. As a result of this "free acceleration", it has been impossible for me to achieve a stable orbit.

This bug is not new for me, I have seen it in many others situations in 1.0, 1.1 and so on. but with just a simple restart it was fixed but now restart doesn't work even I created a new game still it persists.

Those are the only mods I have installed.