This page no longer applies to current versions of CrossOver
This problem is caused by a bug in Lion affecting the memory management within Core Graphics, and in turn affects 3D applications run in emulated virtual desktops in Crossover Games 10.1.1 and Crossover 10.1, which are the earliest versions of Crossover that will run on Lion, at all (any version prior to the aforementioned are unusable on OS X 10.7)
There is a work around for this problem in Crossover Games 10.1.2 and Crossover Standard/Pro 10.1.1. It requires a slight tweaking of the bottle's configuration file in order to implement the fix.
To do so: open up a finder and browse to
/(home)/Library/Application Support/CrossOver Games/Bottles/<bottle>/cxbottle.conf.
(you'll need to hold down the 'option' key while looking at Finder's 'Go' menu to see 'Library')
You can also see this section by going to Crossover's Configure>Manage Bottles section, selecting the appropriate bottle, and then clicking on 'Advanced>Open C: Drive in Finder'. On the same level where you find 'drive_c' you'll find 'cxbottle.conf'.
Open 'cxbottle.conf' in a text editor and add
'CX_LEAK_XPLUGIN_SURFACES'='1'
to the 'EnvironmentVariables' section (and save the file before closing).