Yes, unfortunately you cannot use Greymatter. Greymatter is testing if it can remove (with the command 'unlink') the test file it created. Greymatter needs to be able to create and delete files in order to word.
However, that is a very old version of Perl. Check with your web host and see if they have a new version installed (which would probably support the 'unlink' command).
Can't save the file "/httpdocs/arch/gm-testfile.txt". Please make sure that directory to save the file is CHMODed to 777 and that the file is CHMODed to 666. Also try running Diagnostics & Repair from the Configuration screen.
I have another greymatter blog setup on the same hosting service, although it's an older version, and I never had this problem. Is the hosting services' perl out of date? is there something I can do to fix this? I'm pretty sure I've chmoded everything correctly and I've tried all possible path options.
You could try, I don't think the results will change.
The gm-testfile shouldn't be created by you, Greymatter creates the file then deletes it to test that the directory can be used for storing its files in. I think either the path is wrong or there are permissions ownership issues.
Can you paste in the new error you are getting after removing the gm-testfile you made?