Pantone and the new Pantone+ have wildly different seperations in some cases, different LAB values in other cases. Pantone+ is meant to be a direct successor. I expect more of a storm on this to come throughout this and next year.
My Adobe Pantone Solid Uncoted value for 2955 is 100-45-0-37 and Pantone+ is 83-59-29-10.
I think Pantone is in the wrong with this move, but it's all based around using Pantones base inks to create the color. Seems like if the LAB value is different they are barking up the wrong tree, but it is X-Rite is the one doing the changing. Since they released the color well after CS 5 Adobe can't very well be expected to go with the new color.
I'm hoping Pantone reverts their decisions with Pantone+ personally.
Unfortunately, there are no simple answers here.
Adobe has no control over the Pantone swatches. We pass along whatever Pantone provides us with in terms of CMYK and LAB values for the palettes that are included with Adobe applications. And what Pantone provides in terms of aftermarket palettes is again a Pantone issue. We don't attempt to modify the values in those swatches or reconcile them with comparable colors in earlier library versions.
You really need to bring this up with Pantone.
You should also be aware that for Pantone spot colors, use of CMYK values is very risky. The question become which CMYK colorspace? There is SWOP, Fogra, Euroscale, etc. and the CMYK values from the Pantone palettes are expressed as DeviceCMYK colors. From what we understand, Pantone's CMYK colors are in fact SWOP CMYK. Thus, if you have InDesign or any other CS application setup for any other default CMYK colorspace and/or print with a CMYK characterization other than SWOP CMYK, you seriously risk getting colors that don't closely match what you might expect for either Pantone process color definitions and especially Pantone spot color definitions (which, by the way, are often out of gammut for CMYK process printing). Generally speaking, if you are going to use Pantone or similar color libraries, we most strongly recommend that you set the ink manager to Use Standard Lab Values for Spots.
In this way, you keep your color device independent and either the screen renderer or the RIP (assuming you don't have the spot color itself as would be the case with virtually all digital printing) will do the best possible job converting the LAB color to RGB (for screen) or whatever process color space is being used for printing (which could include colors beyond CMYK such as Hexachrome (CMYKOG) for offset printing or even CcMmYyKk (or similar inks) for high quality inkjet printing.
""The 2011 Pantone CMYK Breakdown for Euro is 100-60-0-53. Adobe CS5 is 100-45-00-37. I just bought pantone color manager hoping this would update this pathetically inacurate breakdown
How have you decided the breakdowns are inaccurate? Any CMYK definition would have to be a simulation of how the color would print on a CMYK press given a specific set of press conditions and not as a solid ink spot color. What are your press conditions? The Lab definition shows that 2955 is out-of-gamut to both SWOP and Euroscale, so it may not be reproducable on any CMYK press.
If your concern is getting the best screen simulation of a solid ink spot, then as Dov suggests the definiton needs to be Lab.