I've been slowly making my way through all the DVD-r's and rw's I can find to see what ones will play on my Tag or Ps2 or Xbox.
Found out that none so far work on the Tag

All but an unbranded one and the White Label ones work on my PS2
And only the TDK and the Datasafe ones work on the Xbox.
Best place to go for your blanks is
www.121cdr.co.uk
Very good service and very cheap prices.
You can get Bulkpaq DVD-R's for as little as 48p each
You might find it easier just ordering up one of all the disks they have a see what works on your player.