I get the following warning when linking against a custom static lib in a release build:

mystat.lib(mystat.obj) : MSIL .netmodule or module compiled with /GL found; restarting link with /LTCG; add /LTCG to the link command line to improve linker performance
Both the project and the static lib are compiled as release (\GL).

#pragma comment(lib, "mystat/x86/Release/mystat.lib")
So what could be the cause of this warnign?
Also: neither the projekt nor the static library are .net.

Sys: win xp sp3, msvc2008pro, native c++.