[Plugin: Visitor Maps and Who's Online] Fatal error: Out of memory

Limit for map pins is set to 40,000
When I lower it, the error message goes away.

How do I keep the high pins limit, without having an error?
is there something i must do to server database, perhaps allocate more memory somewhere?

You gave the answer – allocate more server memory – try 96MB or 128MB if you can!