Heh, I think I figured out something in relation to this packet.
I took the current unix timestamp from here:
http://www.unixtimestamp.com/index.php
Then, I subtracted that from the max unsigned int value of 4294967295.
This gives (for the time I ran this at anyway):
4294967295 - 1294998975 = 2999968320
My thought is that when you log in, it starts sending this reverse timestamp value. I don't know why it sends it, as that info is already handled in the player profile for /played time, and I also don't know why it would need to keep sending it. Maybe they want to make sure people aren't changing their system clocks while EQ is running to prevent some weird hack? It doesn't make much sense to send these in a Move Item packet, unless they want to prevent a hack, since you wouldn't want to block that type of packet.
Another example of this is that my lead GM, Kayen, reported seeing the value 2999989548 sent to him tonight. I checked that using this same simple math and here is the result:
4294967295 - 2999989548 = 1294977747
And using the conversion tool I linked above, that converts to this:
DATE: 01 / 13 / 11 @ 10:02:27pm
Which I think is the time that he logged in.
I can't think of any use we would make of this currently, but I will note it in the source and then apply the patch to prevent the error from happening.
If anyone can think of a reason why they might send these reversed timestamps, maybe we can handle them appropriately (if needed).