Ver 1.3.6 Back Office Issue - Help!!!

[TonyS]

I'm almost at the end of my tether on this issue...

Installed PrestaShop 1.3.6 - Installation seemed ok, front end and back end seemed OK
However, after entering a bit if test data, Customers, Products, Orders etc it got to the point where I needed to FILTER the data in the Back Office to be able to quickly get at what I want. However, it was at this point I realized that the FILTER and RESET buttons do NOT work properly. Clicking them presents a 'White Screen', looking at the source generated it states 'Warning - Invalid Security Token'???

I'm unable to resolve this issue. Tried, logging in/out, Clearing all data in browser cache, to no avail.
I've tried reinstalling to a folder on my domain rather than the root and get exactly the same issue.

I've also tried installing Ver 1.4 RC2 but find it generates the same error(s)

So, whatever I try I am unable to FILTER any set of records in the Back Office of Prestashop. I think it must be something to do with Cookies or Cookie path or a bug in the software, but have no idea how to track this error.

Regrettably, this means we cannot go live with our PrestaShop online store as it would be impossible to administrate it!

DOES ANYONE ELSE, using ver 1.3.6 have any difficulty FILTERING data in PrestaShop Back Office eg, Customers, Products, Employees, Orders, etc

Stumped at present, any help appreciated!!!

FURTHER: Just discovered that, in fact, in back office wherever data is presented in table form I CAN NOT get ANY of the toolbar items at the top of the table to function including First Prev Next Last Page Size drop down Reset or Filter So, for example, because of these issues, just in order to enable/disable countries, in a paged list of more that 200 items, I've had to connect to DB remotely and hack the database direct!

DAM and BLAST! Getting seriously frustrating!

Can anyone stop me pulling ALL my hair out?

Rgds
Tony