With REALbasic 2009r4 there was change with Cocoa memory management. So we changed the plugins to work with that in v9.5. And with v9.6 we changed even more to get less leaks.
Please do not use REALbasic 2009r4 and newer with plugins before version 9.5. You can get crashes there which typically show a line with a objc_msgSend call.
With REALbasic 2009r4 the code below should not be needed as REALbasic runtime does automatically handle the NSAutoreleasePools for you. For older REALbasic versions you need to use code with a timer with the action event below to avoid memory leaks.
// in a Timer Action event:
static LastPool as NSAutoreleasePoolMBS = nil
static CurrentPool as NSAutoreleasePoolMBS = nil
LastPool = CurrentPool
CurrentPool = NSAutoreleasePoolMBS