Ok, so there are more details:
1. debug.err
DebugMessage: Version 0.24 last updated on: Wed Sep 30 15:24:31 2009
DebugMessage: Entering WinMain
DebugMessage: ******* Starting Game Shell *******
DebugMessage: *********DXDiag info follows.*********
System Info
Time: 10/20/2009, 20:34:29
DirectX Version: DirectX 9.0c (4.09.0000.0904)
Machine Name: C3PO
Operating System: Windows XP Professional (5.1, Build 2600) Service Pack 3 (2600.xpsp_sp3_gdr.090206-1234)
Languages: English (Regional Setting: Polish)
System Manufacturer: System manufacturer
System Model: System Product Name
BIOS: Phoenix - AwardBIOS v6.00PG
Processor: AMD Processor model unknown, MMX, 3DNow (2 CPUs), ~3.1GHz
Physical Memory: 2046MB RAM
Page File: 1964MB used, 3000MB available
Windows Dir: G:\WINDOWS
Display Info
Display device 1:
Device Name: \\.\DISPLAY1
Card Name: ATI Radeon HD 4800 Series
Manufacturer: ATI Technologies Inc.
Chip Type: ATI Radeon Graphics Processor (0x9442)
DAC Type: Internal DAC(400MHz)
Key Device: Enum\PCI\VEN_1002&DEV_9442&SUBSYS_20031787&REV_00
Display Memory: 512.0 MB
Current Display Mode: 1280 x 1024 (32 bit) (60Hz)
Monitor Name: M1700
Monitor Max Resolution: 1280,1024
Driver Name: ati2dvag.dll
Driver Version: 6.14.0010.6999
Driver Date: 8/14/2009 04:27:20
DirectX Acceleration Enabled: Yes
Sound info
Sound device 1:
Description: SB X-Fi Audio [AC00]
Default Sound Playback: Yes
Default Voice Playback: Yes
Hardware ID: PCI\VEN_1102&DEV_0005&SUBSYS_00211102&REV_00
Manufacturer ID: 1
Product ID: 100
Driver Name: ctaud2k.sys
Provider: Creative
Driver Version: 6.00.0001.1373
Driver Date: 6/4/2009 02:47:14
Type: WDM
Other Drivers:
Acceleration Level: 3
Cap Flags: 0
Min/Max Sample Rate: 0, 0
DebugMessage: *********END dxdiag info.*********
DebugMessage: Using 4 samples for multisampling.
DebugMessage: Game Resolution: 1280 x 1024 (full screen mode)
DebugMessage: HAL (hardware vertex processing)ATI Radeon HD 4800 Series
DebugMessage: Presentation Interval: Immediate.
DebugMessage: Refresh Rate: 0hz.
DebugMessage: Back Buffer Bit Depth: X8R8G8B8.
DebugMessage: 32-bit z-buffer using 24-bits for the depth channel and 8-bits for the stencil channel.
DebugMessage: ** Checking Direct3D 9 Device Capabilities ************************************
DebugMessage: A full-color cursor is supported in hardware at high resolution modes.
DebugMessage: Bump mapping is supported.
Debug Message: Device is now ready
Debug Message: GFX-THREAD: DISABLED
DebugMessage: RGB in format 6:6:6, Masks reported as ff0000:ff00:ff
DebugMessage: Shell initialization complete
DebugMessage: Elemental: War of Magic is activated.
DebugMessage: ***** Initializing Game *****
DebugMessage: No string tables in G:\Program Files\Stardock Games\Elemental\Data\English/*.tips
DebugMessage: Timer Frequency is 0 369e99
DebugMessage: Initializing sound card.
DebugMessage: initailizing bink
DebugMessage: No files found matching mask G:\Documents and Settings\All Users\Application Data\Stardock\Elemental - War of Magic\screens\*.dxscreen
DebugMessage: No files found matching mask G:\Documents and Settings\All Users\Application Data\Stardock\Elemental - War of Magic\screens\*.dxatlas
DebugMessage: No files found matching mask Music\*.mp3
DebugMessage: No files found matching mask Event Music\*.mp3
DebugMessage: Create anchor mwin
DebugMessage: Load texture atlas.
DebugMessage: InitializeWorld
DebugMessage: Create popup manager.
DebugMessage: InitializeMWinStripEngine
DebugMessage: InitializeMWinDeferredTextRenderer
DebugMessage: Initialize effect system.
DebugMessage: InitializeSpellRepository
DebugMessage: InitializeMusicLayerGroupManager
DebugMessage: InitializeItemModTypeManager
DebugMessage: InitializeMultiplayerClient
DebugMessage: LoadCoreXMLData
DebugMessage: No files found matching mask G:\Documents and Settings\red.13\My Documents\My Games\Elemental\Items\*.xml
DebugMessage: No files found matching mask G:\Documents and Settings\red.13\My Documents\My Games\Elemental\Stamps\*.xml
DebugMessage: No files found matching mask G:\Documents and Settings\red.13\My Documents\My Games\Elemental\Effects\*.xml
Debug Message: Started Load Game XML Thread
DebugMessage: LoadCoreXMLData
DebugMessage: Create setup screens.
DebugMessage: No files found matching mask G:\Documents and Settings\red.13\My Documents\My Games\Elemental\Tiles\*.xml
DebugMessage: Set mouse.
DebugMessage: Set update timer.
DebugMessage: No files found matching mask G:\Documents and Settings\red.13\My Documents\My Games\Elemental\Saves\*.EleSav
DebugMessage: Popup Manager Update: Unhiding LoadWnd
Debug Message: Finished Load Game XML Thread
DebugMessage: No files found matching mask G:\Documents and Settings\red.13\My Documents\My Games\Elemental\Saves\*.EleSav
DebugMessage: Popup Manager Update: Unhiding LoadWnd
DebugMessage: No files found matching mask G:\Documents and Settings\red.13\My Documents\My Games\Elemental\Saves\*.EleSav
DebugMessage: Popup Manager Update: Unhiding LoadWnd
DebugMessage: No files found matching mask G:\Documents and Settings\red.13\My Documents\My Games\Elemental\Saves\*.EleSav
DebugMessage: Popup Manager Update: Unhiding LoadWnd
DebugMessage: No files found matching mask G:\Documents and Settings\red.13\My Documents\My Games\Elemental\Saves\*.EleSav
DebugMessage: Popup Manager Update: Unhiding LoadWnd
DebugMessage: No files found matching mask G:\Documents and Settings\red.13\My Documents\My Games\Elemental\Saves\*.EleSav
DebugMessage: Popup Manager Update: Unhiding LoadWnd
2. In the already presented game (debug.err) I opened the Save window (in the main menu). Every time the same bug (with transparent background) appeared. When I tried new game window, everything went fine. So basically whenever two windows overlap each other, the bug appears.
P.S. My CPU is AMD Phenom II x550 (Black Edition)