Issues using $account on a "Execute custom PHP code" action on event "User account has been created"

Hi there,

Upon a user is created I need to invoke a call to the following PHP function (is part of a custom module of mine):

lsusers_create($uid);

I have created a triggered rule on event "User account has been created" with the action "Execute custom PHP code". I have tried different PHP codes, but none work:

(1)
Code: lsusers_create($account->uid);
Code: lsusers_create([account:uid]);
Result: I cannot create a user. Every time a new user is created I get the error message "Username already exist" (but the lsusers_create is executed properly).

(2)
Code: lsusers_create($user->uid);
Result: no errors but lsusers_create(0); is invoked and I need to pass the real uid to the function to work properly

NOTES.-

- I have been able to create a "Log to watchdog" action which works properly with the content: "The user [account:user] (uid: [account:uid]) has been created"

This seems to me like a BUG but it could be something I am doing wrong. Sorry I am stuck here have not found any solution to the issue.

Thank you so much,
Unai Rodriguez