Yes, I experienced this couple of months ago.
This problem appears sometimes when loading this value from stream and only after Math.MaxDouble declaration was changed (fpc 3.2).
In FPC 3.0.4 (unit math) it was declared as:
MaxDouble = 1.7e+308;
In FPC 3.2 it is:
MaxDouble = 1.7976931348623157e+308;
After that, I changed the declaration of NullDate.
In Lazarus trunk it is no more declared as Math.MaxDouble, but explicitely:
NullDate = TDateTime(1.7e+308);
With this change, the problem disappeared.
So, update Lazarus to trunk or, as a workaround, change the NullDate declaration yourself (datetimepicker.pas, line 55).