Web Speed Optimised with Browser Cache, But some Elements not showing

I have just enabled “browser caching” by inserting the relevant code into htaccess. This increased the speed of my site.

I added this code:

## EXPIRES CACHING ##
<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType image/jpg “access 1 year”
ExpiresByType image/jpeg “access 1 year”
ExpiresByType image/gif “access 1 year”
ExpiresByType image/png “access 1 year”
ExpiresByType text/css “access 1 month”
ExpiresByType application/pdf “access 1 month”
ExpiresByType text/x-javascript “access 1 month”
ExpiresByType application/x-shockwave-flash “access 1 month”
ExpiresByType image/x-icon “access 1 year”
ExpiresDefault “access 2 days”
</IfModule>
## EXPIRES CACHING ##

But since I did that, one element of my website has stopped showing (not always, but often when loading the page). Is adding this code, known to cause problems?

Thanks!