@tiagobeloto – this seems to be getting fixed in 1.6 (see link below) You’d be better off waiting for that release to hit before implementing this.
However, if you need a quick fix until then @r-a-y provided some code near the beginning of the discussion that might help…
https://buddypress.trac.wordpress.org/ticket/2207
Thanks, in this page, i picked-up a plugin to do it this: http://code.google.com/p/l10n-ru/downloads/list?can=2&q=allow
I tested this plugin, now it’s ok. Example: I made a registration with the name “MyUsEr”. Now the bp will accept the username, but in the profile page, the username won’t be “MyUsEr”, will be “myuser”. Why this happen?
It seems to be that way by design.
The plugin is doing what it’s told to do.
Chris, if this is going to be fixed in patch 1.6, what patch are we using now? I’m a noob when it comes to finding that info 
How often is BP patched?
@BlinkyBill01 – You can see the changes that will be in 1.6 here, https://buddypress.trac.wordpress.org/changeset/5443
the red markings is what was removed and the green is what was added,
to find it in the future, it’s usually linked to by a core dev before the ticket becomes closed,
https://buddypress.trac.wordpress.org/ticket/2207#comment:22
…and for anyone thinking of using it on their site for a quick-fix, please note that it’s still in beta and being tested and not guaranteed to work… (theirs a reason it doesn’t get pushed out to live sites automatically)
Since it isn’t a critical bug but an enhancement i’d recommend waiting afew weeks until it’s out officially.
edit: ohhh, right. We are at version 1.5.4 you can see them here – https://buddypress.org/blog/
