It used to happen also on HFW 4.90 with HEN 3.2.0. That's why I have made a reinstall (couldn't find 4.90).
I also had installed Hen Toolbox and that's probably the issue even through it's disabled. By the way I can't uninstall it. I have seen a thread about this and some guy said that reinstall...
Webman mod always uninstalls itself after one or two reboots since I updated to the latest HFW and ps3 Hen release. I have no idea why it happens... I've reinstalled it a dozen times already and also deleted all webman mod files manually through a file manager. Help?