possible http transfer file corruption bug

Greetings,

I'm under the suspicion that lftp corrupts somehow
a file which is transfered via the http protocol
when a transfer is interrupted and continued afterwards
with the -c parameter (e.g. with the mirror command).
I get wrong md5/sha1 sums of the transfered files.

I've been using lftp version 3.0.11 up until now, I've
read the changelogs up to the latest version and didn't
find any bugfixes pertinent to this situation.
The http server in question is apache 1.3 branch.
I haven't tested whether this is present in ftp protocol
transfers.

Any ideas?