You don't necessarily have to accept the year/month schema in uploads. If you go to Options | Miscellaneous, you will note a checkbox there with:
Organize my uploads into month- and year-based folders
Some people prefer just "one big directory" yet others clearly prefer the built in organizer, splitting all your images into months.
Concerning whether or not the web server is able to write to var/www/vhosts/ivobol.nl/httpdocs/blog/wp-content/uploads/2007/10.
Your error message clearly says:
"Is its parent directory writable by the server?"
Two things you must check:
1. Owner/group of the uploads directory (and all below it)
What your local web server needs for owner/group is somewhat variable. It could be "www/www" or "root/root" or "apache/apache" - check your httpd.conf for owner/group and try changing to whatever is set in httpd.conf. That's one approach anyway.
2. Whether the directory permissions are correctly set (as you remarked in your post). Try easing off the permissions like this
chmod -R 777 uploads
"R" is for recursive (meaning all directories below uploads)
That's and an extremely liberal permissions set, but later you can always experiment with tightening things up bit by bit until it's set securely enough yet still allows uploading. If you get the ownership and permissions correct so you can actually do stuff, then (later) try tightening uploads to 775 using the same method as described above.
Sometimes it takes a bit of trial and error, but use these guidelines and you should be on the right track.
Regards & HTH