You may want to try testing with a different hosting provider, such as us:
We offer a 30 day trial on all our accounts, whereby if you cancel for any reason within the first 30 days you owe nothing. That said, signing up for an account and giving it a shot for a month is a risk-free proposition.
Feel free to contact me here or off-list to jmay(at)pointinspace.com with any questions you may have as well.
I would start by opening Activity Monitor (applications > utilities)
Activity Monitor can display in RAM used / reserved / and available.
If the green (available RAM) is gone when you do a standard FMP request, it can indicate you need more RAM or close some open applications before working on the remote database.
I would check on available space on the Boot Partition / harddrive, less than 10% to 15% can cause this.
I would also recommend checking out AppleJack for monthly maintenance.
Lastly, make a new user for testing, logout and login as the test user and test.
This can help diagnose if it is a system problem or a user account problem.
Thanks for the suggestions. I believe I have found the issue which is a bad hard drive. It was not the primary hard drive, but it still was causing problems throughout the computer including filemaker.