The ArraySort (http://www.webalice.it/jj2006/MasmBasicQuickReference.htm#Mb1169) macro misbehaved for QWORD and REAL8 arrays if elements differed only for bit 31 and lower.
The bug is fixed for MasmBasic version 4 September 2012 (http://masm32.com/board/index.php?topic=94.0).
DWORD and REAL4 arrays were not affected. A simple example is in \masm32\RichMasm\Res\ArraySort.asc
Please download the new version. Sorry for the inconvenience :redface: