DVD+/-RW +/-R does not allow drag & drop

[bas1]

Situation:

My Dell Dimensions was equipped with CD ROM in first slot and CD-RW in second slot.

I removed first slop CD ROM and installed Dynex DVD reader writer. Set original CD ROM as primary and Dynex as secondary.

Also purchased Sony DRX 530UL external and it is powered by computer firewire connection.

I am copying photos from my harddrive to DVD for storage. If I put a blank dvd in Dynex Drive E or Sony Drive G and try to access by clicking on either drive in My Computer error message is E or G is not accessible. Incorrect function. So I cannot drag and drop. I can access, the CD-RW drive that was installed when I purchased my Dell and also can drag and drop and copy to CD from there.

The Dynex and the Sony will allow files to be added only through a s/w program. I use Nero.

Is there a reason for the invalid function error and not being able to drag and drop on the DVD drives?

I am using Verbatim +R blank. Also when I access the drive through my computer and select properties, it shows the blank disc as full.

Bev