Which CIFS.NLM should I use?

Server: NW 6.0 sp4 with CIFS PT4 applied

CIFS PT4 has a CIFS.NLM dated 4/8/2004 & 358,552 bytes

NW 6.0 SP5 shows a CIFS.NLM dated 4/1/2004 & 358,630 bytes

BOTH SHOW A VERSION OF 1.50.00 !!!!! Aghhghghrrrr!

I'm seeing far too many CIFS abends. About one every 2 weeks since
applying PT4, but it does solve the WINS registration issue. I would
think that upgrading to SP5 could help, but it only confuses things with
the same version stamp on 2 different NLMs!

Anyone know what's going on with this dual-versioning problem? How many
times has THIS happened in the past?

Any and all help is greatly appreciated.