Hard to explain, but I have a couple screenshots to illustrate.
I'm working on an image. When I go to Develop module, the sliders all look like LR3 sliders. (exposure, recovery, fill light, blacks etc) After attempting twice to update to current process (explanation point) and nothing happening, I made several other adjustments and I was then able to update to current process. Suddenly the slider labels all changed to LR4 appearance (exposure, contrast, highlights, shadows)
If I go back in the history, all sliders revert to LR3 appearance...and vice versa
I now have LR3/4 installed simultaneously! 

iMac OSX 10.7.4
2.4 ghz Intel Core 2 Duo
4 gb ram
LR 4.1
Have had 4.1 for a month, everything works fine.
*edit* I see this is happening with other images too- is this supposed to happen? Weird that I never noticed, if so...
I am running LR with a win7 32bit system and have LR3.6 and LR4.1 installed on the same system.
My LR4.1 behaves in the same way in regards to the appearance of the Development Module:
- pictures from the converted catalog of LR3.6 show the exclamation mark icon at lower right corner and - as long as not updated to new process version - the development sliders are identical to the ones in LR3.6
- after conversion to new process engine by clicking the icon, the sliders do change to the new ones.
- it only seems logical to me that the history module changes the appearance of sliders once you roll back to "before conversion" - to the sliders of the previous process engine.
The only disturbing thing is the fact that you can click this icon without effect. And, you actually can have an effect after doing some adjustments. This part of your posting looks like a bug to me.
Gerd
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