axpde is a steward handling actions done on various wikis. He reported twice (bug 34512 and bug 34381) that a newly created account was not reachable.
Sometime the local account had the user was not attached to the central account. He had to manually request a new password and then merge the account.
In some cases the automatically created account did not even have an email address. Rendering that user account useless.
Bug 34512 is a perfect example. Both accounts on ru.wikiversity.org and kk.wiktionary.org are neither listed on https://meta.wikimedia.org/wiki/Special:MergeAccount nor on https://meta.wikimedia.org/wiki/Special:CentralAuth/Axpde.
One possibility, is that during account creation no userinfo is returned form the CentralAuth database. In such case, we should abort user creation. At least make sure we do not create a user till we have some worthwhile informations.
Version: unspecified
Severity: major