I've tracked down the cause of the random_test failures with some Win32 compilers (Borland and Intel 8 and 9 certainly). Within the test, the random number generator gets passed around by value when constructing a variate_generator. However there are a couple of generators that contain large arrays of long's (the mersenne twister is the first to be tested that has this problem). It's reasonably well known that on Windows, copying large arrays on the stack can overrun Window's stack protection and growth mechanism, resulting in the program trying to write to an invalid address. For the Borland compiler, adding: <linkflags>-lS:8000000 <linkflags>-lSc:8000000 Fixes the regression. For Intel adding: <linkflags>-STACK:8000000:8000000 Works most of the time, but seems to be a bit capricious (it appears you have to delete all temporary linker files before attempting the link, otherwise strange things happen). I'm not even sure if this is the right fix: should we really be passing such large arrays around on the stack in the first place? John.