Node export tips and problems

Currently I am moving nodes from one domain to other, with many images and cck fields. Problem I have other then browser timing out on large files when uploded through node export module is that also on smaller files, with few nodes seems that module sometimes works and sometimes doesnt. What I realized is that if you quickly select code to paste or export file, importing breaks. Like something is proper only after some time you leave it, a minute or so. Maybe this is wrong and doesn't seem smart enough but this is how it seems to me it works.