In case you have a HD2 – regardless of the provider – in the Netherlands please be sure to apply the following hotfixes from HTC; (these updates might also be available in your country, so be sure to hit HTC up at www.htc.com and select your country to check!)
Update for HTC HD2 Opening Java-messages;
http://www.htc.com/nl/SupportDownload.aspx?p_id=297&cat=0&dl_id=921
Even if you do not update anything else, please install this security update. It will prevent your HTC HD2 from immediately (without prompting) opening Java messages, leaving your phone (and data) vulnerable to a lot of exploits, hacks, deletion and so on.
Update for HTC HD2 Music Stability;
http://www.htc.com/nl/SupportDownload.aspx?p_id=297&cat=0&dl_id=938
It still stutters at times, but a lot less frequently
Update for HTC HD2 Car Kit Mode Function Enhancement;
http://www.htc.com/nl/SupportDownload.aspx?p_id=297&cat=0&dl_id=940
Update for HTC HD2 Facebook Albums;
http://www.htc.com/nl/SupportDownload.aspx?p_id=297&cat=0&dl_id=918
There also is a ROM upgrade for Vodafone NL customers, which upgrades your ROM version to 1.72.172.0. Note; this only applies to Vodafone HTC HD2′s and does not apply to any others!
HTC HD2 ROM upgrade for Vodafone NL customers only;
http://www.htc.com/nl/SupportDownload.aspx?p_id=297&cat=2&dl_id=920
Once you have applied these updates, be aware that you will need to apply them again in case you hard-reset or wipe your phone. Of course, this excludes the ROM update for Vodafone. As a tip; the ROM update for Vodafone does not necessarily include the other updates so be sure to apply them as well.