Hi..
It worked but I still have few quick questions...
Here is what I did:
-- Deactivated the plugin.
-- Deleted the files in /tubepress_pro_3_1_1/
-- Downloaded TubePress 3.1.2.RC1
-- Using WP I installed the file (by uploading the zip file via dashboard).
-- Installed & Activated the plugin.
I found the old settings like player size & thumbnial options..etc..
(may be retrieved from the WP DB).
The file & folder were NOT created. So I created them manually in: /public_html/wp-content/tubepress-content/config/boot.json
Now the 1st line of debug log is saying:
[2013-08-31 14:25:36] [DEBUG] Default Boot Config Service: Successfully read boot config from
etc...
Now my last questions:
1- Is it safe if I now turn off debugging now?
2- Is it safe that the location of boot.json is known and readbale to all?
I mean in any WP domain, by default it will be here:
or I should CHMOD the file to something else to allow only tubepress scripts to read it?
3- Where is the default /tmp/ folder?
I couldn't find it... where it is supposed to be?
I read in the dashbaord about Cache directory:
Leave blank to attempt to use your system's temp directory.
Otherwise enter the absolute path of a writeable directory.
where is that "system" temp directory?
the structure is like this:
/home/[username]/public_html/wp-content/tubepress-content/config/boot.json
and
/home/[username]/public_html/wp-content/plugins/tubepress_pro_3_1_2/
Thanks... I guess that's all for this issue 
I have to say that the loading time has been dramatically decreased... I mean really by like 600% (when comparing the footer's XYZ queries in ### ms) I used to have 4 digits there... now it's always 3 digits of ms (less than 1 second)... not complinging 
Best regards
Tamer