esmi, thanks for the quick reply.
- deactivate all plugins, yes i did this previously, did not help.
- switching to TwentyEleven theme, yes did this as well. Site is a bit more normal, however all links still 500 error.
- resetting the plugins folder (did this, didnt fix 500 errors in either theme (my site has been on simpleX 220.127.116.11 for years now, and that is where all my customization work has been done)
- re-uploading wp-admin and wp-includes, did that, no change.
+ idea: might this have something to do with child and parent themes, where updates dont screw up my whole site? I had to something similar with another site i run http://HoneyTrek.com also on wordpress, but that is through Platform Pro, i didnt think i needed to do that with normal wordpress install. thoughts there?
any other ideas?