Last week I had to move some team sites from an upgraded site into a new MOSS site structure. Normally when using the stsadm export function I use the following syntax, which ensures that I move across all document versions, as well as maintain document 'modified by' type information.
stsadm -o export -url http://moss_site/sites/projects/it_projects -filename it_projects.dat -includeusersecurity -versions 4
But this kept on failing for this particular site. On closer inspection of the export log I discovered that one document in the document library had 151 versions!! It was this document that was causing all of the problems.
My solution was to just move across the latest version of the document instead, which has the syntax:
stsadm -o export -url http://moss_site/sites/projects/it_projects -filename it_projects.dat -includeusersecurity -versions 2
Looking back on it now, I could have also tried to delete previous versions, but this could have been a trial and error thing (because I don't know what the export limit actually is - 50 versions? 100 versions? Who knows?)