No Jeff, as I mentioned above, I purposely reset images in LR3 to adobe defaults, including tone curve. The only time that the ver.4 image matches the ver. 3 image, is when there are no additional slider adjustments made to the ver.3 image. Both are at default, AND the ver.4 image has been updated to 2012 process by clicking on the RESET button. Without the reset in 4, they have a very different look and slider settings. Once reset in ver.4 the images just about match (ver.4 in slightly lighter) and of course 4's sliders are centered and tone is linear. This is the only way that they will match. If I bring in from 3 any other way (leaving the exclamation point, no process upgrade) they look very far apart and the sliders are completing different.
I may not be expressing this correctly because the answers don't seem to be directed at my question. If I leave images in PV2010 once they are in LR4, they DO NOT resemble the original images in LR3; a substantial change has occured. They just look very different. Are you suggesting that I continue using LR3 for all those images prior to installing LR4? Because this would be the only way to maintain the way they look with their adjustments. Again, once they are brought into LR4, even with no PV upgrade to 2012, they have been obviously changed, and not for the better. Only, when both LR3 with 2010 and LR4 with 2012 are each at it's own adobe defaults, now when brought into LR4, AND upgraded to 2012 PV does the image in LR4 resemble the one in LR3.