Unfortunately it wasn't going away. I actually found
another post of yours which led me to replace the hotfix with a different one (Update_jailbreak_hotfix_1.16.N_install.bin), and after that one removed the SQUASH JB message, I installed the latest one (Update_hotfix_universal.2.3.2.bin). Aside from a core dump after it rebooted from running the hotfix, all seems good now.
Thanks for pointing me in the right direction!