I just wanted to post this information in case others run into the same issue. I upgraded to Adobe Reader X specifically for the sandbox protected mode feature which immediately errored out and didn't work after installation. I viewed the suggested actions and none of them applied to my system:
After doing a little debugging I found that the previous version of EMET (v 1.2) was still applied to AcroRd32.exe. Even though I've installed and applied EMET v188.8.131.52 the previous version remained applied. Removing EMET v1.x from AcroRd32.exe (image file execution options) successfully corrected the system configuration error I was receiving from Adobe Reader X.
I had deployed EMET previously since Microsoft said in the readme file it was compatible with Adobe Reader. To be fair this was done before reader X was released but I sill would have appreciated some testing on someone's part to find this incompatibility. Hopefully Adobe picks up on this post and updates the above KB with EMET 1.x incompatibility.
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