Andre, as far as I know, partimage is not being actively developed, so I don't think you will get a definitive answer from anyone "in the know" on this project. While I continue to use partimage and have had no issues saving and restoring (mostly) linux ext3 partitions, I haven't used it on Windows NTFS systems. However, it should work. You might try using a different compression level. Also, be aware that if you are using gzip compression, you need to append ".gz" to your image file-name, like "mysavedimage.gz" You shouldn't add the ".000" which partimage automatically adds. Also try re-reading the partimage manual to be sure you haven't missed something.
If those efforts fail, you might try using clonezilla, an open-source project based on partimage. Or if you're willing to use the command line, there is a reliable and actively developed free app called "dd". Of course there are proprietary Windows specific cloning apps too.
PartImage was exactly what I needed, but I am afraid there is an issue of dependability.
It would be great if someone would restart the partimage project. As you imply, it fills a really useful niche.