The version associated with an Export-Package statement can vary depending on the method used to create it. In both cases, the input is identical, but the output is not.
Case 1: Created from packageinfo files in the source tree. In this case, the input of "1.0.0-SNAPSHOT" will be shortened down to "1.0.0".
Case 2: Created from an Export-Package directive. In this case, the input of "1.0.0-SNAPSHOT" will be converted to 1.0.0.SNAPSHOT".
I will attach a small sample project that demonstrates the behavior.