i got this error too : debootstrapping failed
i think there are several parameters:
- size of destination partition
- size of download needed
- sized of installed environment
debian mirrors fail really not, its known to be stable !
(i'm 5 year old debianist)

i try for the 3rd time to install on 1,7 GB ext3 partition...
with "basic" environment...
is there any metapackage for lxde environment later installation?