- September 2009 M1 re-coating; the zeropoints increased by about 0.25 mag in all filters.
- April 2012 M1 re-coating; the zeropoints increased by about 0.2 mag in all filters.
- 2014-08-05 As the VLTSW pl4 was installed the problem with wrong WCS in the headers of the standard star observations started. The pipeline complained that the detected std coordinates are too far off from those in catalog. The data could not be processed and there were no ZPs produced. The problem continued for until end of October 2014. Fixed in PPRS-058455.
- 2015-08-30 All zeropoints at the normal level after GRAAL installed in front of the instrument. No degradation in sensitivity.
- 2015-10-01 New, CASU prepared pipeline (v.2.0.2) adopted. Measurements of the zeropoints differ from previous values.