Hi Paul, I'm using the latest Lurker FW. I had a lot of problems getting the music on. It took me a whole day of having to do it in little chunks onto the SD card as the scan would just hang otherwise. It scans and plays well now that they're all on though but just a right pain to get it done in the first place. I tried all the tricks that people mentioned here but it didn't work. One other annoying thing is that the player won't come on still every now and then unless I open the back up, take the battery out and put it in again (even if it had half a charge). I had a weird thing happen yesterday as well as a certain song playing wouldn't skip even though different songs were showing on screen. I had to restart a couple of times to get it working again. It's all worth the SQ to me though.
You're welcome. It's got a nice warm sound as opposed to the colder ZX1. The bass is tighter and has more body on the DX90, along with more refinement of detail. The treble sounds a little brittle on the ZX1 while it's smoother on the DX90. I was really surprised to hear how better it was to be honest, albeit to my ears. It's all about personal preference at the end of the day though.