Cannot create Printer Context

 今天咨询部的人过来，说培训系统的打印不能用，我过去看了一下，SAPLPD的日志如下：

(11:20:04) Icon DLL loaded.
(11:20:04)
(11:20:04) Network Communication via SAP-NiLib
(11:20:04) Hostname: wangcm
(11:20:04) IP Address: 10.100.46.28
(11:20:04)
(11:20:04) SAPLPD Version 6.28 for Windows/NT (OPT) is listening
(11:20:04) OS-Info: version = 5.1, build = 0/2600, text = Service Pack 2
(11:20:04) Copyright ?1992-2001 SAP AG
(11:20:04)
(11:21:44)
(11:21:44) Receive job for printer DEFAULT (Berkeley LPD protocol / RFC1179)
(11:21:44) send_status called
(11:21:45) send_status called
(11:21:45) send_status called
(11:21:45) send_status called
(11:21:45) send_status called
(11:21:45) Job 000000502200001.STY for user WANGCM queued.
(11:21:45) Start printing job 000000502200001.STY on printer DEFAULT
(11:21:45) Error: Cannot create Printer Context, text = 重叠 I/O 操作在进行中。

(11:21:45) Error: The printer DEFAULT is unknown to Windows Print Manager.
(11:21:45) The following printers are currently defined:
(11:21:45) Printer = \\10.100.46.31\HP LASERJET 1000
(11:21:45) Warning: Printer name contains spaces.
(11:21:45) Please rename printer, before using it from R/3 or UNIX!
(11:21:45) Printer = \\30.0.0.5\HP LASERJET 1000
(11:21:45) Warning: Printer name contains spaces.
(11:21:45) Please rename printer, before using it from R/3 or UNIX!
(11:21:45) Error: BG: saplpd_open_dc failed, msg = 808 SAPLPD:Windows Problem, siehe SAPLPD Protokoll

 

  进入SPAD里查看配置，服务器用的前台打印方式，Host printer 设置为：DEFAULT，记得顾问说过，如果用前台打印，HOST printer 一定要设置为：__DEFAULT 更改设置以后，问题解决，但是具体为什么，我还真不知道，也请明白的人给我解答一下，万分感谢！