Windows XP 上の Visual Studio のデバッガーでハングしたときには、詳細なテキストサービスをオフにする。

Visual Studio Debugger FAQ より。

Why does Visual Studio and the system hang when a breakpoint is hit?
A hang of Visual Studio that also appears to affect the system is can be caused by the use of the Microsoft Language toolbar that is part of Advanced Text Services. This is a known issue that is being addressed by the Windows team.
To workaround the problem, the language toolbar can be disabled.

• Go to the Control Panel
• Choose Regional and Language Options
• Go to Languages tab & click Details
• Go to the Advanced tab and uncheck Advanced Text Services.
• See Nachum Kanovsky’s excellent post about this problem at http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=784282&SiteID=1. An additional resource for this problem is located here at http://www.virtualdub.org/blog/pivot/entry.php?id=118

MUTEX を取り合う感じ？