So, by logging into the server, carefully monitoring the actual
directory contents, I think I see what's happening.

I thought maybe something wrong with my ReleaseBuilder
class>>#transferCurrentPackagesAsUser:password: I used to conveniently
put the baseline versions for 4.5 into the 'squeak45' repository,
because some of the packages appeared to be empty.

So, using just the MC UI by hand, I opened 'trunk', selected
Tools-cmm.519(cmm.518).mcd and copied it to 'squeak45'.

Can we copy .mcd files?  Apparently not -- SqueakSource treated it as
a MCZ and wrote out the contents of the mcd but under the name
Tools-cmm.519.mcz.  Once there, its hard to get rid of.

Until we can get this fixed, please be careful not to copy MCD files!