Java Runtime Environment

We are user Lectora courses published to SCORM 1.2 against our LMS. we find the launching of the courses a bit erratic in that the first time a user tries to launch a course it works and all interactions between content and API are fine, however the second and subisquent times the course runs it locks up at some stage during the course (never the same place). we have ruled out both the lectora course and also the LMS. it appears to be the JRE which is currently available from www.java.com. this version is 1.5.0_02-b05 if i use a 1.4.2 version it works fine every time. the problem is that the version 1.5.0 is the latest!! has anyone else had any experience of this.We are user Lectora courses published to SCORM 1.2 against our LMS. we find the launching of the courses a bit erratic in that the first time a user tries to launch a course it works and all interactions between content and API are fine, however the second and subisquent times the course runs it locks up at some stage during the course (never the same place). we have ruled out both the lectora course and also the LMS. it appears to be the JRE which is currently available from www.java.com. this version is 1.5.0_02-b05 if i use a 1.4.2 version it works fine every time. the problem is that the version 1.5.0 is the latest!! has anyone else had any experience of this.