I first tried a mismatched cid and model id ruu's that was immediately rejected in fastboot. Correct ruu's that match must be signed (by HTC) to be installed with s-on. Hence, the signing error. I found this out, just recently, after posting. The only files I've found so far, that are both match and signed run on a PC (.exe). HTC1guru.com is what I use for files and instructions. I haven't found a matched and signed .zip file. Alternately, I have a few friends with PCs to try with tomorrow: RUU_M7_UL_K44_SENSE55_MR_Cingular_US_4.18.502.7_R1 0_Radio_4T.24.3218.09_10.26.1718.01L_release_35656 5_signed_2.exe
Thanks for your response.