I'm wondering why my daily NetBSD-current sups 
   from sun-lamp are so big. And they always seem to contain
   everything (12000 lines) starting with src/Makefile src/cp src/csh etc.

Well, you haven't exactly help track down the problem any.  Is it
erroring at the end and thus restarting?  Is it `Receiving' or just
`Updating'?  How do you expect anyone to figure out what's `wrong'
with no real information?