No worries, happy to help you get to the bottom of it.
Let’s hope Jonas can too and he hasn’t fully destroyed his life, I mean computer, by disabling the internet 
With USB this is a different story. Keyaspects are
-chipset drivers (how good or how lousy are they, sometimes a MoBo bios update flash could help but usually not much)
-How much other usb devices are attached on the same bus and what is the performance if you detach all other USB devices?
Thanks for all the tips/links etc, cutting of the internet didn’t change anything peak-wise, and I’m too busy right now to do more tests. Will try out detaching usb devices from my lappy tomorrow, though there are only 3 ports on my computer, so I don’t think it’ll do much.
Jonas: Took a look at the crash logs and it seems Renoise simply crashed while saving something, well, as you said, but this is plain scary.
The slowdown that you do experience: does it mainly or only happen with that song?
You’ve reported a few plugin crashers the last days, did this happen with this song?
I know that the more often a plugin crashes, and one gets this detailed message about the crash from Renoise, the more likely it is that one simply ignores the crash and continues working on the song. Most of the time the plugin will only stop working, BUT this actually can break !anything!. Its a bit hard to explain, but maybe this metaphor helps: If a plugin causes a crash, this is a bit like a tiny bomb explodes somewhere in a city. Most of the time it will only nuke a single building, but with a it of bad luck this can also nuke a powerline, so after a while the whole thing ends up in a apocalypse. When and where this happens, is completely random, and there’s nothing we can do against this. Well, expect spitting out a warning that such a plugin crash is nothing you should ignore.
Could you maybe upload the song somewhere, so that we can have a look at it. Of course can also be something fishy in Renoise that has nothing to do with buggy plugins. Would like to double check this here…
Hey Taktik, thanks for your response / concerns.
The few crashes I’ve experienced and have shared on this forum have been with different songs, I’m pretty sure the vopm vsti crash (a few posts back in this forum) was solely the result of that particular vsti and nothing else.
The sluggish instrument list scrolling and automation drawing have been there for some time now, same as laptop fan noticeably blowing after stopping a pattern from playing.
The easiest way to replicate this slowdown / fan blowing, is using Ohmboys Ohmicide.
- Create a new empty song, no vsti or sample importing necessary.
- add ohmicide to a track, open the gui editor and put it on the other screen (if you have a second monitor).
- go to the automation editor and automate a bunch of parameters.
- press play to loop the empty pattern.
- scroll through the instrument list (you must have a default song with a bunch of empty instruments) or draw / drag automation points while Renoise is playing the pattern.
Over here the laptop fan starts blowing like the cpu is doing heavy duty work and automation drawing / scrolling the instrument list becomes glitchy almost immediately.
I was using Ohmicide / automating it heavily in the song that the crashlog above is from, I pressed the saving keyboard shortcut ctrl+s, while the fan was blowing after stopping playback, bammm then it crashed.
This C0000005 business is memory related right? I bet the plugin is leaking or causing the troubles?
edit: am also getting slowdown behavior in songs without Ohmicide or even without having Renoise open at all! Maybe I’ve messed up something in the visual drivers and that is affecting everything? Will check all my hardware drivers soon.
Update:
I think past slowdowns occurred due to some kind of malware or virus in my system.
As of yesterday a new phenomenon has started to occur, every x amount of minutes an airwick freshener audio commercial plays through the speakers!
Now my studio can get funky every now and then, but no need for reminding me with an irritating audioloop!
Browsing google on this doesn’t make me happy, solutions offered are re-writing the rootkit(?) or something …
…maybe some of you have heard of a similar virus playing audiofiles and know a way to get rid of it?
I have comodo installed and while it is able to remove some infected files, during reboot it seems to re-install the virus!
Sounds like Spotify but I doubt it is…
if only it was, but alas… it is called whistler@MBR, some harddisk rewriting thingy, looks like I’ll be spending a night reading up on rootkit-like bahavior instead of breaking beats in Renoise 
Rootkit sucks tremendously, have you tried a bootable Linux USB stick (Or live CD) with a very popular antivirus killer?
That’s usually a good way to get rid of it…
…was relatively easy to get rid of it through tdsskiller: http://support.kaspersky.com/faq/?qid=208280684
one of the weaker type of rootkit infections, or maybe I’m cheering to early?