I think I have a similar problem, but for me it looks very much like PSPad
error:

1. In my test it happens with 200MB file. And even with UCS-2 encoding, PSPad
should be able to open the file - I have more than 1GiB free RAM when I try to
open the file. And I can open the same file twice with two different text
editors simultaneously without any problem.

2. PSPad gives wrong error message: 
---------------------------
Error
---------------------------
Cannot open file ...
---------------------------
OK   
---------------------------
But this happens some time after PSPad has already opened the file and started
reading (I see that RAM usage increasing until the wrong error message appears).
So it's definitely no "open error".

3. PSPad is surely intended to be a programmers editor (even so a very important
hot key for "goto next result" after "find in files" is still missing :-(), and
I think that all users are happy and grateful that Jan Fiala provides this tool.
But it's not reasonable that the users can't use it for any other text files
(which are e.g. used or generated by the program where the user is working on),
as long as there is enough free memory.

-- 
<http://forum.pspad.com/read.php?2,58437,58455>
PSPad freeware editor http://www.pspad.com

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