Nokia 6310i fw 551 - cookies set for +365 days expire after 3 days

Very simple code in ASP, works for other devices (Some motorola).
Nokia accepts the cookie, but if the device not used for ~3 days (powered off) the cookie disappears.
No, I didn't press clear all cookies option.
The time on the server is OK.
The cookie survives power cycle, so maybe it's just 3 days.

Snippet of the code:

<%
Response.Expires=0
Response.ExpiresAbsolute=#May 31,1996 13:30:15#
Response.ContentType = "text/vnd.wap.wml"
Response.Buffer = true
.....
Response.Cookies("user")=CStr(rs.Fields("WapUserID"))
Response.Cookies("user").Expires=Now()+356
%>
<?xml version="1.0" encoding="ISO-8859-8"?>
<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN" "http://www.wapforum.org/DTD/wml_1.1.xml">
<wml>
...

End snippet

The questions are:
1. Is this a know bug.
2. Any official firmware update to make it work.
3. Any other places to ask.

Thanks in advance.

Any ideas?
Any Nokia contacts?
Or is it just "we made this #$!, QA didn't found it, so just buy another device"?

Is 5.51 still the latest fw version for 6310i?

Not sure, but I don't have an acess to any other firmware, as local operator does not have any firmware updates for this model, and I can't upload one from the internet, it will put ~100 devices out of warranty.

Actually i'm already not so curious about the issue, we mad a very bad workaround by saving user credetials in bookmark's querystring instead of cookie. Both solutions are insecure, but the second one is too obvious. All WAP devices I've seen had embarrasing usability/functionality problems. I hope they finally die, so I won't have to explain to clients why it's a bad idea to use WAP for anything, and then implement some stupid workarounds.