Type '' not allowed before login.这是什么意思呀？？

dodoread

数据库SYBASE11.92经常出现如下问题：
00:00000:00032:2005/05/27 10:21:31.03 server  Error: 1621, Severity: 18, State: 1
00:00000:00032:2005/05/27 10:21:31.04 server  Type '' not allowed before login.
00:00000:00032:2005/05/27 10:21:32.03 server  Error: 1621, Severity: 18, State: 1
00:00000:00032:2005/05/27 10:21:32.03 server  Type '' not allowed before login.
00:00000:00032:2005/05/27 10:21:43.28 server  Error: 1621, Severity: 18, State: 1
00:00000:00032:2005/05/27 10:21:43.28 server  Type '' not allowed before login.
00:00000:00032:2005/05/27 10:21:48.38 server  Error: 1621, Severity: 18, State: 1
00:00000:00032:2005/05/27 10:21:48.38 server  Type '' not allowed before login.
相解决但不知问题在哪里，各位大侠谁见过这种问题 呀？？？