setting up custom keyboard/button shortcuts in mediabrowser

when i point my browser to mediabrowser, i notice when i use my left/right arrow keys, it jumps back/forward 4 mins. is there somewhere i can customize this? is there a way to create custom buttons on the mediabrowser window?

[jhb50]

I never noticed that before. Mine jumps 8 mins so it must be based on something else like % of total length. I'm not aware of any customization options.