Can Google give a penalty for websites that use mod rewrites to make pages appear static?

[Spartacus]

Hi, I came across the following when I was looking for penalty causes:

"Masking Issues
When dynamic sites use mod rewrites to make pages appear static, many create ranking issues in the process."

Is this true?

My webhost has a cache (Varnish) for static content that makes the website load faster, I have two websites and on both of those websites make use of this static-content-cache.

I have 2 .htaccess files, one on the root with the following:

ExpiresByType text/html "access plus 15 minutes"

And one in the folder wp-content:

ExpiresByType text/css "access plus 24 hours"
ExpiresByType application/javascript "access plus 24 hours"
ExpiresByType text/javascript "access plus 24 hours"
ExpiresByType text/xml "access plus 24 hours"
ExpiresByType image/jpeg "access plus 24 hours"
ExpiresByType image/jpg "access plus 24 hours"
ExpiresByType image/png "access plus 24 hours"
ExpiresByType image/gif "access plus 24 hours"
ExpiresByType image/bmp "access plus 24 hours"

And 1 of my websites dropped to the last page of google in March and one of my other websites had the same happen just two days ago. Both sites are well seo'd, unique content etc., I paid attention to the things Google likes. So right now I'm clueless and looking for possible causes.

This might be it?

[Spartacus]

I've removed it from my website but am still interested in answers from someone that knows.

[CraigHill]

yes it short mod rewrites will kill your sites ranking.

[snakeyes]

Originally Posted by CraigHill

yes it short mod rewrites will kill your sites ranking.

I haven't seen this happen and i use mod rewrite all the time.

[Spartacus]

Originally Posted by snakeyes

I haven't seen this happen and i use mod rewrite all the time.

Do you use it to make pages appear static?