After doing an "Update DNG preview & Metadata" and "Update to current process (2012)", all unprocessed RAW files now look like if auto tone were applied, all sliders in the develop module are at 0 and for some unprocessed RAWs the white balance is now at 3950 (which is incorrect for those photos). When I change some develop settings and then "reset" the pictures, I get the 0 sliders and auto tone effect right back.
This wasn't so with 4.0 where for unprocessed RAWs the develop sliders weren't all at 0 but at different values (never had a RAW yet where sliders were all at 0) and they usually were slightly underexposed. What I see now are overexposed pictures, and I have no idea what the "original" looked like in terms of exposure. I begin to doubt that if I get such strange results with 4.1, maybe there are other bugs as well for development and I can't trust what I see.
Sounds like you're comparing Process Version 2012 vs an older PV (like 2010). For PV 2010 the default slider values in the Basic panel were often non-zero (e.g., Brightness 50, Contrast 25). In PV 2012 the default values for all the Basic tone sliders are zero.
First and foremost I want to make clear that I'm speaking of LR 4.1 RC1 when I speak of "LR 4.1" in this context.
Guess the problem is that in contrast to LR 4.0, in LR 4.1 all development sliders seem to be forcedly auto-positioned to 0 for unprocessed RAWs. While I can understand this, I don't know why some of my unprocessed RAWs now have a white balance of below 4000, they had around 5500 in LR 4.0 before.
Because all my RAWs usually had values for exposure in the negative range in LR 4.0, their previews looked darker and more pale. In addition, I got an impression of what the original settings for contrast, highlights, shadows etc. were. That's no longer possible with LR 4.1 because a kind of auto-tone is applied without having selected that. The original look of the unprocessed RAWs is gone, and the sliders values are lost that way. White balance is a real problem, I get values in LR 4.1 that are absolutely incorrect (too low) and have lost their real values.
That's completely new for me, didn't have this with LR 4.0 or 3.6. Wish I could get the previous way how the development sliders worked back. Is this a bug in LR 4.1?