As this forum is completely quiet anyway it cannot hurt much
I removed the registering link from the guest screen,
In skin_global Template: +--Guest Bar (function Guest_bar)
changed
( <a href='{ibf.script_url}act=Login&CODE=00'>{ibf.lang.log_in}</a> | <a href='{ibf.script_url}act=Reg&CODE=00'>{ibf.lang.register}</a> )
to
( <a href='{ibf.script_url}act=Login&CODE=00'>{ibf.lang.log_in}</a> )
This way I can change it back later