I get quite a lot of invalid results.
At least the ones I checked are always 1 linux (my one) against 2 Windows boxes.
So I assume my linux box is generating something different than the windows boxes
Janus could you check on the DB is this assumption is true?
Might this be connected to the "native" setting?
Any other idea?

Thanks

From what I can see your computer seems to be producing invalid results, not sure why, but it's worrying for the projects that don't require verification where you've been marked as valid.

What distro are you using and have you tried installing Blender via apt/otherwise?

I just found one which is valid, even against a windows box.
I'm using debian unstable.
No I don't have blender installed otherwise.
But starting blender from the projects dir (after unzip) starts and I get something. So I assume there is no lib missing (in native mode). Installing additional libs might change the results, but I would be surprised.
Installing blender now, let's see.

Installing Blender is the easiest way to make sure you have all the required libraries assuming you're running an Xorg desktop (which you are).

There are also certain tasks which still show discrepancies between Linux and Windows, which isn't your fault.

e.g.
http://burp.renderfarming.net/workunit.php?wuid=2114675
http://burp.renderfarming.net/workunit.php?wuid=2115068
http://burp.renderfarming.net/workunit.php?wuid=2115059

All being marked invalid after comparison to 2 Windows clients. This is a Blender issue to my knowledge, but I couldn't tell you if one is more "correct" than the other.

Question is, what to do now.
I don't like to spend all this time(cpu cycles) for nothing.

Nothing you can do. The system will sort itself until this specific project is finished. This isn't a common issue so I wouldn't worry too much about it.

This isn't a common issue

Sure?

I had this now for some sessions, so there is something more general, than one session.
Maybe my computer(-setup), but which part, so I can fix it.

I only see it happening in 2148. The last time I witnessed it was several months back. It might be related to blur.

as well session 2113.
But obviously this only happens if burp validates the resultst, which is not that often the case.
So we don't know for the sessions without verification.

For the part which causes this, I don't know blender details, so I can not comment on this.

Looks like others have the same issue:
http://burp.renderfarming.net/results.php?hostid=61091&offset=0&show_names=0&state=4&appid=