Not Allowed to Insert Blank DVD+R

When I attempt to insert a blank DVD+R I get the error message "This operation cannot be completed because you do not have sufficient access privileges."

1) I am the administrator on this computer (and the only user). This is a new problem.

2) In "System Preferences/CD/DVDs" I have set "Open Finder" as my preference for how to handle blank CDs/DVDs.

3) In "System Profiler" I see the DVD media shown correctly, but there is no disc icon on the desktop. (Discs with content do show correctly.)

Info: Early 2005 PPC PowerMac 2.7 GHz G5, 5.5 GB RAM, 250 GB HD, 1 TB internal HD, ATI Radeon X800 XT graphics. Running Mac OS 10.4.11.

From System Profiler:

TSSTcorp CDDVDW SH-S222L:

Firmware Revision: SB03

Interconnect: ATAPI

Burn Support: Yes (Vendor Supported)

Profile Path: /Library/DiscRecording/DeviceProfiles/PatchBurn-tsstcorpcddvdwshs222l.drpr ofile

Cache: 2048 KB

Reads DVD: Yes

CD-Write: -R, -RW

DVD-Write: -R, -RAM, -RW, +R, +RW, +R DL

Burn Underrun Protection CD: Yes

Burn Underrun Protection DVD: Yes

Write Strategies: CD-TAO, CD-SAO, CD-Raw, DVD-DAO

Media:

Media Type: DVD+R

Blank: Yes

Erasable: No

Overwritable: Yes

Appendable: Yes

Opening Toast 9, and attempting to write TS files to the (invisible) disc, Toast sends the error message "Mac OS Error (-50)."

Any ideas? Thanks!