If your polarization D-term solutions (in the antenna file or PD table) have any failures and hence magic blanks, the polarization application code did not pay attention to them. Hence D-term values > 30000 instead of around 0.03 or so were applied. This bug has been fixed in 31DEC17 and 31DEC18 versions of AIPS. Use a MNJ to update your version. Eric Greisen