There are a few changes you might notice as we move into the new 4.1 patch.

Option settings
The former Video, Sound, and Voice Chat menus have been consolidated into a single streamlined menu called Options. Graphics, Advanced Graphics, Sound and Voice will be sections accessible on the left side of the Options window along with one new panel: Network.

The new Network panel currently only has two options.

Optimize Network for Speed: This will be on by default and should reduce latency for most players with high speed connections by increasing the amount of information sent between the game client and the server. It will only impact latency in instanced Dungeons, Raids, Battlegrounds or Arena battles. If you are using a low speed connection and begin seeing issues loading into those areas after the patch, please try disabling this option.

Enable IPv6 when available: This option will be disabled at launch as networking upgrades are still required before it can be used. For more information on IPv6, please check here:
http://us.blizzard.com/support/article/IPv6



Known Driver/Compatibility Bugs
We are aware of a few issues that are coming out with this patch. These are still being worked on but most have a workaround.

Washed out Game Announcements: You may see Battle.net announcements and some achievement notifications become very washed out and unreadable if you mouse over them.

Triple monitor crashes: World of Warcraft will crash when using AMD Eyefinity and Radeon HD 5000 series cards if set to 5760x1080. There is no current work around besides reducing the game resolution.

Water flickering and lighting: When water is set to 'high' detail, you may notice flickering along the edges of water that gets worse as you pull back. Also, players using Radeon 9600 XT (AGP) or Radeon X550 (PCI-E) may notice odd lighting when looking at water.

Shadow flickering with Crossfire: When using AMD HD Radeon video cards in crossfire with shadow quality set to high you may notice flickering issues with the game shadows. The current workaround is to disable crossfire
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Technical Support
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Check your G-diffuser system!
Edited by JonD on 5/20/2011 3:01 PM PDT