well I know I have a problem with computers, cuz they tend to behave in a really weird manner as soon as I get close to them. but still, it doesn't explain everything, esp when working remotely with ssh. anyway:
default docs directory for my apache server was
/var/www/ www-data:www-data (755)
I didn't like it, so I copied the whole dir elsewhere
and changed the config of the server to use it as default dir, chown'ed and chmod'ed recursively it to the correct values.
When trying to view the page, got an error 403.
I checked the config, could not see anything different between the two dirs, which where an exact copy of each other.
I changed the apache config to use /var/www/ as the docs dir, it worked
changed the apache config to use /home/.../docs/ as the docs dir, it worked NOT
changed the apache config to use /var/www/ as the docs dir, it worked NOT ANYMORE
changed the apache config to use /home/.../docs/ as the docs dir, it worked STILL NOT
...and it still doesn't work since then
so is it just me or is there something wrong
hum, I either got inspired, or my server decided to be nice with me
I chmod'ed the parent dirs o+x, now it seems to work. hope it helps other people too