I have seen a problem around logging in, but I am not sure what it is.
Last weekend, I had a marathon email correspondence with a fellow owner of our group who owned and monitored the group on Y! for two decades. I would call him a "digital immigrant", not nearly a digital native, but certainly minimally literate.
He could not figure out how to log on to our group site on grio. I am not sure where the confusion arose, but the man struggled. His account was set up properly with a password. Although he changed his password, his old password seemed to retained somewhere, perhaps in a browser cache, but perhaps not, Eventually I realized that he was logged in, but did not recognize it.
Since our discussion was all email and he tried several things before he got back to me each time, reconstruction is not possible, but I agree that taking users consistently to the group home page would help.