Hi Kartu,
Thank you for your codes, they are working as expected.
I don't think fb2 is known by a lot of ebook readers in China. People prefer pdf and epub because of their availablility (especially pdf). Some local manufacturers also bring support for zip/rar format, which is popular for manga. I think another important missing feature in PRS+ is support for djvu. (Another effort which you probably know, ebookapplication.com, has introduced such features). I will definitely try fb2 anyway.
By the way, do you mind looking at some css from the epub I have? As I mentioned, before I used the script, the user css in /database/system/PRSPlus/epub/whatever.css enable my 600 to display some Chinese epub files correctly while other not; after I used the script, the user css seems to be skipped, and epubs previously OK cannot be shown while those used to be messy now can be shown.
I checked several files, and found that,
the previously OK files do not specify fonts in their internal css (and they were displayed according to my user css before I use the script)
the previously NOT OK files did specify fonts and their path (and they could not be shown since I did not have correct system font then before I use the script)
it seems to me that after I run the script to define system fonts, the user defined epub css is skipped.
examples:
previously OK:
http://textsnip.com/89e17d
http://textsnip.com/3b0385
previously NOT OK:
http://textsnip.com/a4a4dc
Not sure if it is anothe bug...