Errorcode: TWAIN-Driver give an unknown code

When I use the TWAIN-driver unter X7 (Draw also as Phot-Paint) I got the errer - code, that the TWAIN-driver give an unkwown code out. WIA.Drive will run, but as ADF the functions are not very good. Sorra, my English isn't so good, but I hope, someone can help me.

Greeting Friedhelm