Hello Wayne: Thank you very much for the fix - Shift Match now works, but Network Anchoring tool still gives this error: Model read finished. Duration 0.629954099655 Model validity check skipped CcpNmr Analysis Version 2.0. Release 6 (Copyright 2003-2009 CCPN) Distribution created Wed Jan 28 17:39:59 2009 If you use this software, please quote the following reference: Wim F. Vranken, Wayne Boucher, Tim J. Stevens, Rasmus H. Fogh, Anne Pajon, Miguel Llinas, Eldon L. Ulrich, John L. Markley, John Ionides and Ernest D. Laue (2005). The CCPN Data Model for NMR Spectroscopy: Development of a Software Pipeline. Proteins 59, 687 - 696. The FAQ is at: http://www.ccpn.ac.uk/ccpn/software/ccpnmr-analysis/faq For further help see the mailing list: http://www.jiscmail.ac.uk/ccpnmr >>> Exception in Tkinter callback Traceback (most recent call last): File "/usr/local/ccpnmr/python2.5/lib/python2.5/lib-tk/Tkinter.py", line 1403, in __call__ return self.func(*args) File "/usr/local/ccpnmr/ccpnmr2.0/python/ccpnmr/analysis/popups/CalcDistConstraints.py", line 1421, in runAnchoring structure=None, nexus=None) File "/usr/local/ccpnmr/ccpnmr2.0/python/ccpnmr/analysis/core/NetworkAnchoring.py", line 98, in networkAnchorAssign progressBar=progressBar) File "/usr/local/ccpnmr/ccpnmr2.0/python/ccpnmr/analysis/core/NetworkAnchoring.py", line 930, in getCloseSingleShiftMatches resonances.append(resonance) UnboundLocalError: local variable 'resonance' referenced before assignment >>> Cheers, Vitaliy