hmm... MobiPocket 5.1 works on my Cingular 8700c but it's unlocked and using Telstra 4.1.0.309 but I would thin if it works on 309 it should work on 304. I can download and read ebook stuff but not .pdf or .doc (which is the only real reason I downloaded MobiPocket. In another thread someone said they used it to read .pdf's & .doc's, but I can't do that.