the first question is whether {PS_Y_GIFT.ENTRY_DTE} is a date field or a datetime field?
If it is datetime then the range should also be in that format.
{PS_Y_GIFT.ENTRY_DTE} in Date (2000,04,01) to Date (2001,05,31)
this expression ultimately is translated by Crystal to
{PS_Y_GIFT.ENTRY_DTE} >= Date (2000,04,01) and
{PS_Y_GIFT.ENTRY_DTE} <= Date (2000,05,31)
So normally I present my date selection in this format and it gets passed down to the server with no difficulty.