Can't get HTTP payload modification iRule to work

Thanks for your help. I'm able to collect 2750 bytes of data, then call TCP::release and the page displays. However the page still breaks if I actually modify anything. If I comment out the actual replacement command then it works OK (but of course the page is not modified). Here is the code fragment:

 

 

 

when HTTP_RESPONSE_DATA {

 

log local0. "$uri;$my_id;$time: Entered HTTP_RESPONSE_DATA"

 

set indices [regexp -all -inline -indices {/intl/en_com/images/logo_plain.png} [HTTP::payload]]

 

foreach idx $indices {

 

set start [lindex $idx 0]

 

set end [lindex $idx 1]

 

set len [expr {$end - $start + 1}]

 

 

log local0. "$uri;$my_id;$time: Found String, len=$len"

 

HTTP::payload replace $start $len "http://kaybee.org:8080/google_f5.png"

 

}

 

HTTP::release

 

}

 

 

So this code works since the replacement line is commented out. And I see the log entry showing it found a match. So what could be wrong with my replace command?

 

 

Thanks in advance!