show less priority to non-professional features like Facebook and Flickr exporting.
That I would wholly agree with, especially since those features are so terribly poorly implemented. Jeffrey Friedl's plugins run rings around the native Lightroom implementations that are buggy and very frustrating.
I even applied a more "conservative" process to the image, using only the default LR sharpening (25, Radius 1.0) and I'm still seeing an orange shift, so that excludes that theory.
If you are still seeing a pronounced color difference in exported JEPGs with normal sharpening and Fill (less than 50) settings, it again indicates a monitor profile issue. I'll suggest one last time (3rd time) changing your monitor profile to Windows sRGB profile to see if that corrects the differences. Your monitor will no longer be calibrated, but what you are trying see is if the exported JPEG and original RAW file now look closer to each other in LR when using a known good monitor profile. I provided a link showing how to do this if needed. Please let us know your results using one of your problem images with the suggested "conservative" LR adjustments.
out of curiousity, can you post a screenshot of your export dialog? I am running into this exact issue; and no, I don't think you are crazy or have suddenly gotten a bad monitor profile. I wonder if there sRGB profile that is being used for the JPEG export is the issue, however.
I believe we have finally identified the root cause of the OP's problem. Please review my bug report at this link and 'Add your vote' by clicking on the +1 buttom at the bottom of the post:
If you have any questions please let me know.