stupid Raid question...

[Sukurachi]

I normally just dual-box my way through older raids to get stuff like pets and mounts.
then I realized that most of the toons I'm dual-boxing could easily solo the old raids.

So I went with a pair of toons I normally dual-box, and entered solo with one, did the first boss then exited.
Then I entered with the 2nd toon, solo, and did the 1st boss.

So far, so good.

But now... they can't enter together to continue the raid despite both being at exactly the same place in the raid?

They are both "locked" to the raid, having each killed the 1st boss, and nothing else.

I though that as long as you were at the same place in the raid you could join up with other people?

[Lisaara]

I know in instances that worked but I think they removed that sort of thing from older raids OR it wasn't implemented until later.