The Hidden Forest

I had a character sitting in the zone from a few days ago and I had a toon in the vale and in the forest respectively and when I tried to zone them into the zone they both went into a separate instance. To correct this I had to zone everybody in from the same zone for them to be in the same instance.
I use UF client if this makes any difference and I have all files updated. I did not try this with any other client so I am not sure if it makes a difference. I am also fairly certain that have zoned toons in from different zones before when they have all gone in the same zone but this was not like that.
Is it a bug or did I just always zone in from the same zone before?

I've had a similar issue. All my toons zoned in from the GH but the one that was camped in ToV logged in to a different instance. Unfortunately for me, that was my mage who was there to coth. I plowed thru the zone and then camped the mage again. When I went back two days later, they all ended up in the same instance which was nice. I'm wondering if it's a time issue - if you don't log them in after a few days, they end up in different instances. Or, it could be a boo-boo in which case I blame everyone but me. =D