Keywords: system, cgxco, dsp
CORE Generator has an option to open the last project used, when it is first invoked. If System Generator is opened with a design that uses an IP core, between invocations of CORE Generator, COREGen will be opened with the project just produced by System Generator.
A list of the most recently used projects is available under the File menu. Choose the desired project from this list, or browse to the project using the File -> Open Project selection.
The option to always open the last project can be turned off by selecting File -> Preferences... and de-selecting "Open Previous Project on Startup".
This issue is resolved in ISE 9.1i design tools.