scratch disks full error with photoshop cs

Just installed Photoshop CS. On running a simple script to make a 40cm jpg I’m getting a “scratch disks full” error message when resizing the image by 50% - which of course they are not . . .

set ruler units of settings to percent units
resize image docRef width 50

error -	"Adobe Photoshop CS got an error: General Photoshop error occurred.
  • Could not complete the command because the scratch disks are full."

Testing further, this only seems to happen when resizing with a percentage -

The scripts all worked fine with 7.0 . . . and everything works fine with cs using it manuallly . . . anyone come across this? Got any ideas?

thanks

Solved this myself . . . in CS, to set 50 percent, you now put .5 - 1 is 100 percent etc. So trying to resize 50 really did fill the scratch disks . . . .

is this a bit weird??