We've exported some lists from one site collection SC1 in web application WA1 with the Export-SPWeb command, and imported it in site collection SC2 in web application WA2 with the Import-SPWeb command.
After some tests, we've discovered that some urls found in rich text or link fields have been changed this way :
1) For urls with _layouts
2) For urls without _layouts
Does anyone have an idea about what's happening and how Export-SPWeb and Import-SPWeb affect links and urls in list fields values ?