Hi Dreamer. You should really have spoken to your retailer or distributor about this as your warranty is with them, however AJ is correct and you should be using 4.2B which is stable and can be downloaded from
www.ketron.it.with regards to the corrupt style, it should be enough to insert the 2012 pen drive, change to D:remov and select the "00KTNinstall" file to reinstall the style pack. There is no need to UN-install first.