I'm facing to a strange problem: cvs corrupts rcs file while I'm trying to tag it. The file itself is about 50Mb (and it's binary) and rcs file is about 2.1G.
Every time I launch
cvs rtag -B -a -F -r 1.526 -b "my_tag" project/file.bin
rcs file turns from 2.1G into 110K file with completely lost history and file itself. All other operations (commit, update, etc) works fine. This is the biggest file in repository and the only file with such behavior on tags. Others are working fine.