Has anyone been able to access the pre installed Yahoo Messenger powered by OZ on the T Mobile Pocket PC?

I have seen lots of discussion concerning Yahoo Messenger and Pocket PC. The downloads at Yahoo are really inadequate. Agile MEssgnger is super, but they want a per month charge now which i would not mind paying except i use the program infrequently. I have also used the Yahoo Wap and this is not a good option either. My question: On the T Mobile Pocket PC installed with the MDA, there is a messaging program called powered by OZ. It prompts me to select AOL, ICQ of Yahoo messenger. AOL and ICQ work, but have not been able to log on to Yahoo. I had a previous Pocket PC from T Moble, a HP IPAQ and it worked just fine and was a full featured Yahoo Messenger. Is there a trick on how to access the Yahoo messenger pre installed. I am wondering why Yahoo does not have a downloadable pocket pc messenger. Help Please!

I use the Oz version from my phone without any problems. However if you go to yahoo mobile from a PC and enter your phone info it will give you options of what version to use. All you have to do to get started is put your number in and they will send you a text with an address to log in.