I don't have any personal experience with your config but found this on the compatibility page:
ACS control on Windows NT, 2000 and 2003 requires LibAttach software from STK. Support for ACSLS 7.1 starting with NB_45_6_F NB_50_1_M.
Support for ACSLS 7.0 starting with NB_45_5_M, NB_45_5_F NB 5.0.
Support for ACSLS 6.1.1 starting with NB_45_5_M, NB_45_5_F, NB_34_5 NB_341_5.
Support for ACSLS 6.1 starting with NB_45_2_M, NB_45_3_F, NB_34_4 NB_341_4.
It is also noted that NBU testing for 5.1 was done with version 1.9.52
Hope that helps