URI keeps adding values as form validation fails

[eluser]RJ[/eluser]
Hello,

Sorry so many posts today, having some issues and difficulty resolving permanently. My URI looks like:

s/en/shop/device

the device method looks like

function device($dealer = '999', $page = 'personal_information', $debug = FALSE)

upon form validation failure the URI changes to

s/en/shop/device/999

if it fails again the uri looks like

s/en/shop/device/999/999

Is me setting a default value in the var the cause of this?