[LAD] is this a compiler issue??

Hello all, i have written a channel class, which collects data from (file) sources and copies it to a buffer. Jack will get this buffer and put it into his streams. So far, I think, this is a normal design with the following code for (unsigned int n = 0; n < nframes; ++n) { pBuffer[n] += pFrames[n]; pBuffer[n] *= volume; } i know, it's not really optimized. But it works as an example. as you can think, pBuffer and pFrames are float* and volume is also a float. now it happens, when the volume is 0, after 3-5 seconds, the CPU will run into 100%. a workaround is the following before the loop if(volume < 0.0000001) volume = 0.0000001; But i try to understand, what happens here. Is the compiler overoptimizing zeros. compiler is: $g++ -v Using built-in specs. Target: i486-linux-gnu Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj- c++,treelang --prefix=/usr --enable-shared --with-system-zlib -- libexecdir=/usr/lib --without-included-gettext --enable-threads=posix -- enable-nls --program-suffix=-4.1 --enable-__cxa_atexit --enable-clocale=gnu -- enable-libstdcxx-debug --enable-mpfr --with-tune=i686 --enable- checking=release i486-linux-gnu Thread model: posix gcc version 4.1.2 20061115 (prerelease) (Debian 4.1.1-21) what puzzles me is, that this doesn't happen on my double core system. Any ideas. Thanks c~