2
are you using the xoopsheadlines module? If so try turning off the block on the front page to see if that makes any difference.
Basically performance is affected by 3 main things:
1. Current Load on Web Server (Apache, IIS)
2. Current Load on DB Server (MySQL)
3. Responsiveness of external content (RSS Feeds, Weather Feeds, etc).
the first two can be measured and controlled, but the 3rd is largely out of your control. As such it is usually the first suspect when troubleshooting performance issues. If you are unsure if you have modules or blocks that rely on external content, I recommend a methodical approach.
1. Remove every block from your front page (except for maybe the login, mainmenu blocks)
2. Measure response time
3. Add 1 block to the page
4. Measure response time
Repeat steps 3 & 4 until all blocks are back in the page. Normally you will find that once a certain block is enabled performance degrades noticably.