I currently have "Allow Capital Letters in Username" and "Network Username Restrictions Override" installed on my multisite/members install and I have used them without problems in the past.
It appears as though the "Membership" plugin has its own authentication filter and does not recognize these exceptions and therefore it will not pass the custom username through to WP and instead it throws up its own error message. (a poorly formatted one without a clear explanation as to why for the end user I might add)...
Potential members are going to use capital letters no matter what instructions or disclaimers we put on the forms and I don't want them becoming frustrated with error messages that are not well formatted or clear - when almost every other site on the internet now allows for capital letters.
Can you help me?