Map rewinds on 1.2.3 CB dev update

Hey,
I am having problems whenever I try to update my server to 1.2,
as the title says, my map rewinds back 10 days or so, which is a lot of work gone.
So I would like to know if this is normal on the map generation or is it a craftbukkit issue?
or if the problem is on my part.
BTW I tried deleting some old files that have been modified a while ago, but still no effect.
Thanks in Advance!

 

If you have tried converting your world already, restore from a backup that existed before you first tried 1.2.

Then try the conversion again with the latest Beta build (or the very latest dev builds - b2063 or higher.)

 

Wait, is the build #2060 the first beta or second?
Since my mc server hoster only offers that build...

 

b2060 is the second beta build.

 

I did that, but still. the second beta is the only update i tried.....