Tim, I'm having a similar problem to the one Justin reports with the Follow Shift Changes. I'm looking at a series of 12 HSQC spectra (+1 reference), using the Ax/(1+Ax) fitting function. I tried to "Group Peaks" twice, with different results. The first time, the process started properly, then hung for at most a couple of minutes at about 18%. After that, Analysis just quit without warning. Traceback: /usr/local/ccpnmr/bin/analysis: line 8: 25146 Segmentation fault /usr/bin/python -i -O $CCPNMR_TOP_DIR/ccpnmr1.0/python/ccpnmr/analysis/AnalysisGui.py $1 $2 $3 $4 $5 The second time, the process crashed at about 60%. I waited for half an hour but it did not recover and I had to kill analysis. No traceback. - Martin