Synchronize Drums and Bass

Hi everyone! I use Cubase with Arturia Spark and Image Line Groove Machine as my VSTi drum machines. I'm mostly composing electronic dance music (Trance). I control each of them with the Behringer FCB1010 MIDI foot controller using the M-Audio MIDISport 2x2 Anniversary Edition USB-MIDI-Interface. So Pattern 1 of e.g. Spark is triggered by the Button 1 on the FCB1010 and so on with a total of 10 patterns I can switch between. Pattern 1 is my main drum loop, Pattern 2 is a variation of it, Pattern 3 a fill etc. When I want to record the drums I create a new bus in Cubase and then I route the drum machines to record on an audio track. That works but that's not the problem. Now when I record an arpeggio bass, like e.g. from a VSTi plugin (controlled by my Yamaha MM6 keyboard) reFX Nexus or Sylenth1, it isn't synced with the drums after I listen to the recorded track. Nexus and Sylenth1 are synced with the master clock of Cubase. Spark and Groove Machine as well. Even if I quantize audio, the bass and the drums are not in sync. Sometimes everything is in sync when recorded, sometimes not. :( It's totally random. And I want to finally solve this problem to know that everything will be in sync from the first time. (Example here: http://www.youtube.com/watch?v=OzSeYxRu3TY , it's a sound demo of the 7 Skies Trance expansion and you can hear from the beginning that the bass is synced to the drums all the time.) I was wondering if it has something to do with latency problems. But I don't think so as I'm using a Creative SB X-Fi Titanium soundcard with a latency of 4 ms with its Creative ASIO driver. So I thought that I have to record the drums on MIDI to sync with the bass. That actually works but it's too tedious placing all the drum elements into the internal drum editor and then quantizing the bass and the drums to make sure they are in sync. Also, when I possibly want to add some fills or something like that, it would be too hard doing all that. So my question is: Is there any possible way to record the VSTi drum machines on a MIDI track instead on an audio track or any other way to get rid of this annoying problem? How do you guys do that to make sure your bass in sync with the drums? Thank you in advance. If something is unclear, please tell me or ask questions. I can also provide screenshots if needed. I just want to get rid of this annoying problem.

Nope, I don't know how to do sidechain in Cubase at all...