I've noticed this occuring several times with Regulus. At various points in a game, for a brief period, ai regulus' will not show the movement animation as they move around - instead, the animation will be stuck in the standing still position, but will teleport very short distances to keep up with the actual location of the regulus (kind of like the bug with the scout in tf2).
dxdiag:
----------------
System Information
------------------
Time of this report: 9/8/2008, 15:53:02
Machine name: VERSPUNKEN
Operating System: Windows XP Professional (5.1, Build 2600) Service Pack 2 (2600.xpsp_sp2_gdr.070227-2254)
Language: English (Regional Setting: English)
System Manufacturer: System manufacturer
System Model: System Product Name
BIOS: Phoenix - AwardBIOS v6.00PG
Processor: Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz (2 CPUs)
Memory: 2046MB RAM
Page File: 1068MB used, 2870MB available
Windows Dir: C:\WINDOWS
DirectX Version: DirectX 9.0c (4.09.0000.0904)
DX Setup Parameters: Not found
DxDiag Version: 5.03.2600.2180 32bit Unicode
------------
DxDiag Notes
------------
DirectX Files Tab: No problems found.
Display Tab 1: No problems found.
Sound Tab 1: No problems found.
Music Tab: No problems found.
Input Tab: No problems found.
Network Tab: No problems found.
--------------------
DirectX Debug Levels
--------------------
Direct3D: 0/4 (n/a)
DirectDraw: 0/4 (retail)
DirectInput: 0/5 (n/a)
DirectMusic: 0/5 (n/a)
DirectPlay: 0/9 (retail)
DirectSound: 0/5 (retail)
DirectShow: 0/6 (retail)
---------------
Display Devices
---------------
Card name: NVIDIA GeForce 8800 GT
Manufacturer: NVIDIA
Chip type: GeForce 8800 GT
DAC type: Integrated RAMDAC
Device Key: Enum\PCI\VEN_10DE&DEV_0611&SUBSYS_23301682&REV_A2
Display Memory: 512.0 MB
Current Mode: 1680 x 1050 (32 bit) (60Hz)
Monitor: Plug and Play Monitor
Monitor Max Res: 1600,1200
Driver Name: nv4_disp.dll
Driver Version: 6.14.0011.7519 (English)
DDI Version: 9 (or higher)
Driver Attributes: Final Retail
Driver Date/Size: 5/16/2008 14:01:00, 6108928 bytes
WHQL Logo'd: Yes
WHQL Date Stamp: n/a
VDD: n/a
Mini VDD: nv4_mini.sys
Mini VDD Date: 5/16/2008 14:01:00, 6557408 bytes
Device Identifier: {D7B71E3E-4551-11CF-6D68-3B0303C2CB35}
Vendor ID: 0x10DE
Device ID: 0x0611
SubSys ID: 0x23301682
Revision ID: 0x00A2
