Out of Memory but memory usage low

Hi All,

I recently moved host and since then I am receiving frequent connection “time out” errors. I am on a VPS. However, I have set both memory usage and connection time quite high in PHP.ini and I still get the problem. To confirm this, my XML Sitemap trouble is also having problems and kindly gave me the following report:

The last run didn’t finish! Maybe you can raise the memory or time limit for PHP scripts.
The last known memory usage of the script was 24MB, the limit of your server is 256M.
The last known execution time of the script was 18.18 seconds, the limit of your server is 180 seconds.

Any ideas anyone?

Thanks