Lost ability to access iTunes via Airport after Force Quit - Network issue?

Question

I am not sure if this is iTunes or networking related, but all other networking appears ok.
First my setup: multiple machines use iTunes library from an external HD connected to Airport Extreme, OS 10.4.11, iTunes 7.6.2.
I had been updating ratings in the iTunes library on the external drive connected to the AE and I was connected to the AE via Ethernet with Airport Card on PB turned off. I went to move the PB to another location so I turned Airport Card on and disconnected the Ethernet cable with the iTunes app and database open (dumb move apparently). The iTunes app appeared to lock up along with the PB, I was able to force quit thru it, and now I have an unresolved issue that has me stumped.
After numerous restarts of the PB, I can access the iTunes library on this AE server via the ethernet connection (as it was before attempting to move), and all of the ratings I had changed appear to have been saved. But I can not get iTunes to access the library via wireless (Airport Card).
I have restarted the AE and the connected drive both. I have restarted the PB numerous times. If I login on PB with ethernet connected there is no issue, if I login with airport active only there is an issue. All attempts to start iTunes and accessing the library wirelessly result in no success, sometimes can quit normally, sometimes must force quit. I can option start iTunes to access/create library on internal drive and also can create a new library on the external AE server. Also all other wireless networking activity regarding that server has no issue (access , copy, move files etc...)
I've tried removing iTunes pref files in user library and that didn't fix anything. The application itself works fine with the database when connected via ethernet or with internal library.
Anyone have any clues or suggestions on where I should turn to try and fix this? I can try to provide more details if needed, but I am stumped short of potentially aggravating the issue with re installs and other potential attempts that may not even be related to the issue.
Thanks

Answer 1

No disk maintenance recently. I have a week old backup of the entire iTunes folder along with the Library. I tried moving that backup Library (file only) into the AE server location but that did not change anything in terms of access.
I am on lunch break so no time to try your suggestions immediately, but will later this evening. I had thought about trying with a new user but hadn't gone there yet. I also have a G4 iMac ethernet connected all the time to the AE, but it has a AE card also typically not in use. I tried accessing with the iMac machine wirelessly, and although it progressed further (got the iTunes menu bar to display - never even got that on the PB), iTunes was not able to load which makes it almost seem not machine specific but rather something with the AE settings or the usb connected drive, but again all is fine there via ethernet.
Last night after original post, on the PB, I thought about a corrupted keychain type thing perhaps not allowing file access wirelessly, and I did have something to repair there, but it did not solve the issue.
Again, thanks for the suggestions and I'll try later tonight. Let me know if my additional info sheds any further light or if it would indicate that the suggestions were on the wrong track.
Dave