I have also encountered this freeze problem with the v2.18 Mission Editor; AH locks up and remains unresponsive for several minutes, or indefinitely, when a warp segment begins. On one occasion the mission did resume after a fairly long freeze, but on all other attempts I've had to shut down Aces High manually using the Windows Task Manager. This only occurs when the mission is run in AH; no problems with warp segments when running them in the ME.
Both converted 2.17 missions and newly created 2.18 missions render the same freeze result, but I have found that this only happens when the player aircraft's flight enters the warp segment. On non-player routes & flights, the warp segments work normally in the game. I created a mission where enemy aircraft warp but the player does not and the warp segments performed without a hitch.
Graphic detail is set to default/middle of the road settings with display set to 1280 x 800 viewed on a 1280 x 1024 external monitor.
------------------
System Information
------------------
Time of this report: 3/23/2010, 20:11:17
Machine name: DJMG3XD1
Operating System: Windows XP Home Edition (5.1, Build 2600) Service Pack 3 (2600.xpsp_sp3_gdr.091208-2036)
Language: English (Regional Setting: English)
System Manufacturer: Dell Inc.
System Model: Inspiron 1520
BIOS: Phoenix ROM BIOS PLUS Version 1.10 A09
Processor: Intel(R) Core(TM)2 Duo CPU T5250 @ 1.50GHz (2 CPUs)
Memory: 3838MB RAM
Page File: 689MB used, 4518MB available
Windows Dir: C:\WINDOWS
DirectX Version: DirectX 9.0c (4.09.0000.0904)
DX Setup Parameters: Not found
DxDiag Version: 5.03.2600.5512 32bit Unicode
---------------
Display Devices
---------------
Card name: NVIDIA GeForce 8400M GS
Manufacturer: NVIDIA
Chip type: NVxx
DAC type: Integrated RAMDAC
Device Key: Enum\PCI\VEN_10DE&DEV_0427&SUBSYS_01F11028&REV_A1
Display Memory: 256.0 MB
Current Mode: 1280 x 1024 (32 bit) (60Hz)
Monitor: Plug and Play Monitor
Monitor Max Res: 1600,1200
Driver Name: nv4_disp.dll
Driver Version: 6.14.0011.0128 (English)
DDI Version: 9 (or higher)
Driver Attributes: Final Retail
Driver Date/Size: 6/6/2007 17:34:38, 5465472 bytes
WHQL Logo'd: Yes
WHQL Date Stamp: n/a
VDD: n/a
Mini VDD: nv4_mini.sys
Mini VDD Date: 6/6/2007 17:34:38, 6345472 bytes
Device Identifier: {D7B71E3E-4767-11CF-1873-FA2100C2CB35}
Vendor ID: 0x10DE
Device ID: 0x0427
SubSys ID: 0x01F11028
Revision ID: 0x00A1
Revision ID: 0x00A1
Video Accel: ModeMPEG2_A ModeMPEG2_B ModeMPEG2_C ModeMPEG2_D