Exporting and Importing web permissions

[justmike2]

I wanted to create a moss2007 dev environment with a subset of data from the production content db's. I created a copy of the content db's and removed all the webs via stsadm. I then exported a subset of data from the prod content db and imported it into the Dev db. That all worked fine, however the permissions seem to been broken in all the subsites. Did I do something wrong or is this the way it works?
I am reletively new to sharepoint, so i apologize if this is too vague..

Wondering if I should have removed the site collection from Dev also then imported that then the individual webs?

Here are example commands (the names have been changed to protect the innocent)
Remove web
""C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\BIN\STSADM.exe" -o deleteweb -url "

Http://servername/sitecollection/name"

"

Export
"C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\BIN\STSADM.exe" -o export -url "

http://servername/sitecollection/name"

-filename "\\%FileLocation%\C$\_ExportImportDB\Data\name_4.bak" -overwrite -includeusersecurity

Import
"C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\BIN\STSADM.exe" -o import -url "

http://%ImportLocation%/sitename/name"

-filename "\\%FileLocation%\C$\_ExportImportDB\Data\name_4.bak" -includeusersecurity