Now I found that the font that books and scrolls use cannot be simply assigned by a xml and usually people take the "DarNified Books" tweak of Wrye Bash to fix this problem. So far, it works fantastic, but nevertheless a problem occurs because I did what I explained right above. All the texts now in books and scrolls use the third font (sfontfile_3=) and what I simply want is to make them use the second (sfontfile_2=) instead. I really don`t know how Wrye Bash works or what it does, when it applies the DarNified Books tweak, but would it be possible to make it change the font it assigns from the third font (sfontfile_3=) to the second font (sfontfile_2=)?
I think it would make more sense if you made your modifications to DarN so that it will comply with what Wrye Bash (and DarN) expects.
I suspect my Bash problem has something to do with my double Python (26 & 27) installations in which the 27 is 64-bit version (with wxPython 2.9). I'm not sure if Wrye Bash is supposed to work nicely with 64-bit version of Python though.
Holy moly. Are you looking for help or just documenting your trials?

The officially supported versions are Python 2.6.5 and 2.6.6, wxPython 1.8.11.0 ANSI, ComTypes 0.6.2, PyWin32 and Psyco 1.6. All 32 bit.
64-bit may work but it's not supported.
PS.
Psyco will not work on 64-bit setups OR with Python 2.7 (32 or 64-bit). It's only optional, but if you already have it installed, Wrye Bash will try to use it.
You can force Wrye Bash to not use it by specifying the 0 (zero, stands for zero optimization) argument on the command line.
EG. c:\python27\pythonw.exe "Wrye Bash Launcher.pyw" 0
yup that did the trick, thank you

so any reason why this file caused this problem?
That file is used to to tell bash that it's already running, in case you try to run two copies of Bash at one time.
There is a small bug where the file is not always properly deleted after Bash closes (eg, when Bash crashes). So Bash thinks it's already running even though it is not, and it refuses to start again.
This is fixed for v291. We hope.