If restarting the server clears up what's going on, I'm not sure that you're seeing memory problems. I'd suggest hitting the sys.dm_os_ring_buffers[/url] to determine if you're getting out of memory alerts. If not, while you may be experiencing memory pressure, causing paging, etc., you're not actually literally running out of memory.

It sounds more like you may be experiencing other issues such as bad parameter sniffing or something else. Have you looked at blocked processes, wait stats, query execution times?