[Baz Praz]

I've been using Calibre for several years now without any problems - UNTIL RECENTLY.

Since the installation of v2.56 64bit - everytime that I start Calibre, Avast analyses calibre-parallel.exe.

I installed v2.57 64bit and got the same problems.

If I click on a book to read it - I get the message "calibre-parallel: calibre-parallel.exe - Application Error"
&
The instruction at *** referenced memory at *** The memory could not be written.

A similar problem arises if I try to add a book - Avast analyses calibre-parallel.exe and calibre produces the following message:-

calibre, version 2.57.0
ERROR: Errors while adding: Failed to add any books, click "Show details" for more information
----------------------------------------------------------------------
Failed to add the book: *** ***
F:\***.epub
With error:
Traceback (most recent call last):
File "site-packages\calibre\gui2\add.py", line 371, in add_book
IOError: [Errno 2] No such file or directory: u'G:\\Swap & Temp\\calibre_525c8i\\emzx0h_add_books\\0.cdata'


----------------------------------------------------------------------
Failed to add the book: *** ***
F:\***.epub
With error:
Traceback (most recent call last):
File "site-packages\calibre\gui2\add.py", line 371, in add_book
IOError: [Errno 2] No such file or directory: u'G:\\Swap & Temp\\calibre_525c8i\\emzx0h_add_books\\1.cdata'
-----------------------------------------------------------------------
I've tried uninstalling -including removal all remaining folders - and reinstalling from scratch with no improvement.

PLEASE - can anybody suggest what I can try next?

Baz