mixing Debug and Realese builds of a library not working?

[Martin O]

Am I required to use debug version of a library with a debug application utilizing that library and vice versa?

By the way, my libraries are all statics .lib files.

I'm not sure if its a requirement, but I do it anyway. To make it easier I change the output file of the debug version of the static lib to mylibd (I add 'd' to the end of the .lib name). Then in the application that uses the static lib, I use mylibd.lib for the debug config & mylib.lib for the release config.