problems with time outs in combination with IBM Websphere

Hi, we have IBM Websphere web servers behind a load balancer. We also make use of an application which is written for IBM Webshere. We've already encountered quite a lot of problems, but the most of them were solved already within the application. At this moment we experience a strange kind of problem which is very difficult to reproduce. That is that some users will get a time-out in their browser after clicking on a submit button within the application.

We somehow suspect the persistence profile the VS is making use of. This is a UIE profile with an Irule as configured by the Webshere design guide "Deploying F5 with IBM WebSphere 7" Sometimes we see in the persistence records view sessions with the same JessionID on different VIPS. Here is an example:

0000zAvlbCrwb7FW2ARCs7iHGYF:-1 Universal vs_A-SSL Pool_A 192.x.x.x:9080 140 seconds 0000zAvlbCrwb7FW2ARCs7iHGYF:-1 Universal vs_C-SSL Pool_C 192.x.x.x:9080 137 seconds

The irule connected to the Universal profile looks like this:

when HTTP_RESPONSE {
if { [HTTP::cookie exists "JSESSIONID"] and $add_persist } {
persist add uie [HTTP::cookie "JSESSIONID"]
set add_persist 0
  }
}
when HTTP_REQUEST {
if { [HTTP::cookie exists "JSESSIONID"] } {
persist uie [HTTP::cookie "JSESSIONID"]
} else {
set jsess [findstr [HTTP::uri] "jsessionid" 11 ";"]
if { $jsess != "" } {
persist uie $jsess
}
}
}

We tend to assume that the duplicate JessionID's could be the source of our time-out problems some users get. Are we on the right track?