The product is IAS 6.5 sp1 mu4 and turn off dynamic re-loading.
jdk : 1.3.1_11-b02
Java flag include -XX:+PrintCompilation

Sample jsp code
-----------------
<%@ page contentType="text/html; charset=utf-8" %>
<%
for (int i = 0; i < 1000; i++) {
    int dataCount = 0;
    java.util.List dataList = new java.util.ArrayList();
    dataCount = dataList.size();

    if (dataCount > 0) {
        Object tmp = new String[dataCount][2];
    }

    for (int k = 0; k < dataCount; k++) {
        dataList.get(k);
    }
}
%>

 When the jsp is compiled, load and run for the first time,  the indexOutOfBoundsException is thrown
 Running the same piece of code in Tomcat, work well. 

choon-  xxxxx@xxxxx   2004-04-13

1.  Turn on dynamic reloading of jsp ( IAS feature )
2. Modified the jsp to
-----------------
<%@ page contentType="text/html; charset=utf-8" %>
<%
for (int i = 0; i < 1000; i++) {
    int dataCount = 0;
    java.util.List dataList = new java.util.ArrayList();
    dataCount = dataList.size();

    if (dataCount > 0) {
        Object tmp = new String[dataCount][2];
    }
  else
            System.out.print("");

    for (int k = 0; k < dataCount; k++) {
        dataList.get(k);
    }
}
%>
--------------------
3. create a .hotspot_compiler with the following lines

exclude jsp/APPS/fortune/fortune _jspService

choon-  xxxxx@xxxxx   2004-04-13

See the suggested fix section.

  xxxxx@xxxxx   2004-05-27

dd