Many flights that I have looked at on OLC, posted by various pilots using diverse equipment, displayed with grossly incorrect altitudes. This is using the OLC online display that shows a small map and a small altitude graph. Usually, if incorrect, the displayed altitude in some parts of the flight is much (3x) lower than reality. If I download the IGC file from OLC and look at it in other software I can see the correct, higher, altitudes. Thus it is an OLC web page bug, not incorrect data in the flight logs stored on OLC. This has been happening for at least 3 years, in both OLC 2.0 and OLC 3.0. Is it just me? Is anybody working to fix this bug?