This is the OpenWeb proxy, not a real device. You should contact the network operator and ask them to whitelist your sites.
You might find useful these two articles we published on mobiForge.com:
Content Transformation Addendum to Web Browsing Style Guide
Setting HTTP headers to advise transcoding proxies...
Please note that the practices suggested here are for XHTML only. If you serve any WML/WAP 1 pages you should not use the Cache-Control headers suggested in those articles. If you do not get whitelisted, you will receive this user-agent string and a generic HTTP request FROM ANY mobile device and will not be able to detect it.