Code:
	site grpadd AAA
200 Group 'AAA' successfully added.
site grpadd BBB
200 Group 'BBB' successfully added.
site gadduser AAA test test *@*
200 User 'test' successfully added.
site user test
200-.----------------------------------[uINFO]------------------------------------.
200-| Login: test                           Group: AAA                            |
200-| Unfo : No Tagline Set                 Flags: 3                              |
200-|                                                                             |
200-| Credits:          0MB                 WkUp:          0MB                    |
200-| Ratio  :  Unlimited                   WkDn:          0MB                    |
200-|                                                                             |
200-| Ip1. *@*                              Ip2.                                  |
200-| Ip3.                                  Ip4.                                  |
200-| Ip5.                                  Ip6.                                  |
200-| Ip7.                                  Ip8.                                  |
200-'-----------------------------------------------------------------------------'
200 Command Successful.
site chgrp test AAA BBB
200- User 'test' has been successfully removed from AAA.
200- User 'test' has been successfully added to BBB.
200 Command successful.
site user test
200-.----------------------------------[uINFO]------------------------------------.
200-| Login: test                           Group: BBB                            |
200-| Unfo : No Tagline Set                 Flags: 3                              |
200-|                                                                             |
200-| Credits:          0MB                 WkUp:          0MB                    |
200-| Ratio  :  Unlimited                   WkDn:          0MB                    |
200-|                                                                             |
200-| Ip1. *@*                              Ip2.                                  |
200-| Ip3.                                  Ip4.                                  |
200-| Ip5.                                  Ip6.                                  |
200-| Ip7.                                  Ip8.                                  |
200-'-----------------------------------------------------------------------------'
200 Command successful.
 Works just fine here in 4.9.4r. But it might be worth looking into. Strange things has happened to io before after some uptime.