Index: branches/eam_branches/20091201/ppStack/src/ppStackMatch.c
===================================================================
--- branches/eam_branches/20091201/ppStack/src/ppStackMatch.c	(revision 26785)
+++ branches/eam_branches/20091201/ppStack/src/ppStackMatch.c	(revision 26794)
@@ -278,5 +278,7 @@
 
             psKernel *kernel = pmSubtractionKernel(kernels, 0.0, 0.0, false); // Convolution kernel
+            bool oldThreads = psImageCovarianceSetThreads(true);              // Old thread setting
             psKernel *covar = psImageCovarianceCalculate(kernel, readout->covariance); // Covariance matrix
+            psImageCovarianceSetThreads(oldThreads);
             psFree(readout->covariance);
             readout->covariance = covar;