Rather than trying to explain this myself, I rather point you to this:
http://www.langer.camelot.de/GenericsFAQ/FAQSections/ParameterizedTypes.html#Can%20I%20create%20an%20array%20whose%20component%20type%20is%20a%20concrete%20instantiation%20of%20a%20parameterized%20type?
Harald.
BioMed Information Extraction: http://www.ebi.ac.uk/Rebholz-srv/whatizit