deploy war with ReadyApi results in memory leak

Hi

With SOAPUI pro we deployed our stub to a tomcat

Now on the SOAPUI NG (ReadyApi) version we encounter some problems 

We noticed leak of memory before but it was minimal

Now we use SOAPUI NG the leaking increased what results that after a few minutes the tomcat runs low on memory en stops

aug 12, 2015 4:41:52 AM unknown unknown

SEVERE: Unexpected death of background thread ContainerBackgroundProcessor[StandardEngine[Catalina]]

java.lang.OutOfMemoryError: Java heap space

At first the tomcat memory pool was set to a maximum of 250MB but when we increase it to 1000 MB is only postpone the problem for a few minutes.

Is this a known bug or does anyone kwon how to solve shis?