File boxes don't remember last location

Hopefully I can describe this so it makes sense...

A couple days ago my Mac started acting funny in file boxes– by file box I mean the dialog box that pops open when you do File > Open, or File > Save As, etc. It defaults to my users\documents folder every single time I do one of those actions, regardless of what I'd done before.

So let's say I'm working on a document, and want to save it. I'll do an option+S to save it, the window comes up in users\documents, I navigate to where I want to save it, and save. Now the next time I go to "save as" the document, before this week that dialog box would've started in the location I last saved the file– now, it defaults back to users\documents every single time. Needless to say, this is incredibly annoying and adds precious time to my process every time I want to open or save a file.

I've tested it and just about all of my programs seem to be having that problem: Word, Photoshop, Indesign, etc. I can't think of anything I've done this week to suddenly make it act up like that. Can anyone think of why it'd be doing this, and what I might do so it remembers last locations again?

(I'm currently running OS 10.4.9.)

Thanks,
m19

Does anyone have any ideas? I'd be more than happy to give more information if the problem isn't clear– I'd really like to analyze why this is happening so I can fix it.

m19

I think I've discovered yet another piece of the puzzle...

First off, in Photoshop I opened a file off our Design drive (a network drive all our designers have access to) then did a Save As, which is how I normally work. It defaulted back to the users\documents folder when I did the Save As, like it's been doing problematically. But next, I opened a file sitting on my desktop instead, then did a Save As: this time, it remembered that I was looking at the desktop instead of starting in the users\documents folder. So that worked like it's supposed to!

What this tells me is that it's not really program-related at all, but is rather a function of the network drive: for some reason, my programs suddenly don't remember it as where I've been, if I'm working on a file from it. It seemed like it was program-related because sometimes it would work normally (when i was working off my desktop) and sometimes it wouldn't (when I was working on the network drive) but I wasn't aware of that pattern.

Opening or saving files locally from my computer works flawlessly as it should: it remembers the last folder I was in every time, so long as I don't access the network drive. So that being the case, that gives me a definite direction to pursue. I don't suppose anyone is familiar with any issues remembering folders on a (PC-based) networked drive?

m19