Mass Mail stuck in loop if >455 users selected

Using:
Joomla v1.5
CB v1.8

I discovered today that if you select (not just filter, but SELECT) over 455 users and try to Mass Mail to them, the function fails, by repeatedly sending to only the first set (the first 50, if you use the default). This can be tested in simulation mode too, so no need to spam 50 users over and over again.

Is anyone aware of this problem, and is there a patch planned?

Thanks!

Alan

Works ok on our site here on Joomlapolis.