Laggy Frame Drop Jittery even on title screen

[Gryffyn]

     I am playing a heavymod game. It (the game) has been running very smoothly and I have not had any problems what so ever. The other night I was flying a Command Pod to my space station. I docked just fine, transferred my crew, then undocked and as I fired my rcs retrograde I noticed that the game started running real laggy.  1 in game second would take 3 or 4 real time seconds to pass. I figured my heavymod setup finally caught up to me or the high part count. Wasnt that worried about it. I went ahead and painfully waited for my craft to get out of physics range of the station to see if it would speed back up to normal but it didn't. Again I went ahead with my rentery and landing in Super Happy Fun Time Choppy mode. It was late so I was going to shut game down and troubleshoot the problem the next day and when I was at the title screen I noticed that the rotation of Kerbin was choppy and as the kerbalnauts moved across the screen they were choppy too. I closed down the game and then reloaded it up and the choppyness was still there. I made a brand new sandbox save and loaded it up, built a small rocket and launched it, and it was real choppy as well.

     After all this narrative my question is this. Even though everything was running completely flawless, could it still be mods that cause everything, even the title screen, to run perma-chop? Out of the blue?  I've dealt with high part count, and over-mod issues before. I'm not new to it, but this just feels different and I don't have the knowledge base to begin troubleshooting coding or physic time rates and such. I will start the long process of kicking mods out but I just don't see that being the problem. I haven't added anything new mod wise for a long time, not even any updates for my mods, and as I said before everything was running great, then BAM.... I'm stuck with perma-chop. If anyone has ideas I am all ears, otherwise, if I am lucky enough to find the problem on my own I will let ya'll know. I may try a clean install first with what I call my "Base Mods" first and see what happens. (Base Mods are ones I can't live without like Navyfishes' docking indicator and docking sounds. Mostly just fluff stuff...... er wait why am I rambling I'm sure ya'll don't care and I have work to do! lol) 

[Benoit Hage]

I'm not sure of what is happening to your game, but I'd say have a look at your task manager while your game is laggy. Then you'll be able to tell if it is the game which takes all your resources away or an other program.