How do I delete files from HFS+-formatted network drive

Relevant system components:

• Very recent iterations of a MBA and MBP both running 10.7.4
• Cisco Linksys e4200v1 wireless router, FWver1.0.04
• Seagate 1.5 Tb FA GoFlex external drive
  • Full-size, single partition reformated by DiskUtility to HFS+ (Mac extended volume, Journaled)
  • Connected by USB to storage port on e4200
  • Storage set to share at root with either Anon r&w access or admin level user acct.
  • Demonstrated read and write access

I have set up an external drive as above. The drive is to be used to archive large amounts of uncommonly used data (not a backup) and then is backed up to crashplan+ off-site.

The drive came formatted as FAT32 (I believe.) As we still have one PC and all individual files are smaller than 4Gb, I set up the archive drive as formated out of the box.

Data was written to the drive without issue, backed upi off-site with no issue and accessed a couple times.

The issue came when recently upgraded some itunes albums. These albums had been previously removed from the library and from the computer and stored in the archive drive. These albums were upgraded and redownloaded from apple generating a copy of the album data, but in a superior format (no-drm, greater sampling rate.) This made the archived files obsolete and generated a risk of mixing versions. I decided to delete the obsolete files from archive.

When I attempted to do this by selecting, right-clicking and chosing "move to trash" I was prompted that this was not a "undo-able" action, suggesting that while I was selecting "move to trash," the action would not generate a copy in the trash. Next I was prompted to enter my user and PW. The only user and PW combo that would not cause the dialog to "shake it's head" at me, was my computer user-specific password. The network or drive associated user and PW combos would not take. When I entered my computer user and PW, it was accepted, but a dialog labeled "Trash" popped up with small font, reading "The operation can't be completed because you don't have permission to access some of the items."

Trying to delete only a random selection of one or two files would not work.

I checked the drive permissions and was only able to see "You have custom access." This is not modifiable. I attempted to alter my access permissions from the router, but made no headway. Again, I could read and write, as the router setup suggests, but not "modify," to use a windows term.

Assuming, with little data, that the FAT32 was perhaps at issue I unmounted the network drive, connected it by USB and reformated as above. After formating, I tried the same procedure with no change in outcome.

I am nearly 100% sure that when the drive was connected by usb, I could delete to my heart's content, but not when it is connected via network.

I will note that the drive is accessed by first connecting to the router, which the mac sees as a "PC." This access can be controlled, but can be set to anon.

When I connect I see two identically named folders. One is a sharepoint folder and one is a volume. They access the same data. Deleting thorugh either route has identical outcomes.

As I am a complete newb to Macs, I am really not sure where I should even begin to look for access. Should I bind my router access to my user acct? Is this even doable? Can I reset permissions to this folder through the terminal? Is this really a Cisco or Seagate issue?

Any knowledgable advice is appretiated. I can do the speculating.