(Just updated to 5.4.2 from 5.4.11, if it matters)

I changed the timezone for me (user/admin), and when I went to save it, I got an error msg saying that my username (admin_*****), that I've used since I created the site, could only have alphanumeric characters in it.

I fixed that with no problem--but what's this all about? Is it new, or is it a case of dashboard-editing requiring different protocols than elsewhere?

If someone has an answer, I'd appreciate it...discrepancies like this freak me out a bit. ;)

Thanks!
Nick