The following is what is written in the book can some one throw in their expertise.
The context is method call from CMT bean to BMT bean method
"When a transaction is suspended, it waits until it can pick where it left off. But this means that the things that happen while the transaction is suspended are NOT part of the same atomic unit. In other words, the things that happen while the transaction is suspended won't be rolled back if the suspended transaction (after it comes back to life) fails to commit"
?1) When a transaction is suspended what can be going on ?? which will not be part of "atomic unit" ... i mean is in't blocked.... waiting.... no action