put this in the contructor of the class that will be the background thread:

NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
[NSThread detachNewThreadSelector:@selector(threadMethod:) toTarget:self withObject:nil];
[pool release];



then in threadMethod


- (void)threadMethod:(id)param
{
	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
	while (YES) {

		[NSThread sleepForTimeInterval:(float)SLEEP_TIME];
		//dostuff
	}
	[pool release];
}