8x8 Matrix, only half the LED's at full brightness

Ok so I’m new to this so please go easy on me. This is my 4-5 project with my new Arduino Mega2560 board and I’m following a tutorial from http://oomlout.com/8X8M/8X8M-Guide.pdf.
ok so i have built the breadboard up as described and double checked all my connections twice now.

THE PROBLEM.
So i have uploaded the sketch from http://tinyurl.com/yjozkrr to my board at that went through with zero problems but my 8x8 matrix is only lit on the bottom 4 rows as if you were looking from above. The top 4 rows are lit but very dim. Now these rows are connected to PWM pins 13-8 so i tested these with a simple blink LED test and they light the LED to 100% brightness???? so i tried the Knight Rider array from the examples and this works fine on PWM pins 7-2 but if i move and alter the sketch for PWM 13-8 i get dim led's.

Am i doing something really stupid here or am I just not understand the board and the sketch??

All Help given will be appreciated.
Many thanks!!

One common cause for very dim outputs is failing to call pinMode(pin, OUTPUT), so you only get the weak internal pullups sourcing current.

MarkT:
One common cause for very dim outputs is failing to call pinMode(pin, OUTPUT), so you only get the weak internal pullups sourcing current.

Cheers I will check that out, like I said new to it but learning through trial and error and laughing at my stupidity all the way

Video off my problem