Did you get the link on your BB or did you tell yahoo to send you an SMS with the link from your desktop pc?
I've had that problem too, I just deleted Y!IM and with BB Browser, downloaded from Blackberry Site:OTA
Here are my setting "options" I use while Y!IM is running
Show Offline Contacts-Yes
Show Display Images-Yes
Show Conversations in Message List-Yes
Other than that not too many options you can configure. Hope the reinstall will help.
Edit: Are you running Y!IM as a separate app? or are you logging in via SMS to 92466?
If your running Y!IM separate and it still not working a quick fix would be this:
* From your phone
Text in [Yahoo! ID] [password] to 92466. Do not include quote marks, brackets or commas. For example, if your Yahoo! ID is chatsalot77 and your password is 123456, your text should read : in chatsalot77 123456. Leave a space between in, your Yahoo! ID and your password, as illustrated.
You will receive a text message confirming that you are logged into Yahoo! Messenger on your mobile device.
Once you are logged into Messenger on your phone, your Yahoo! Messenger contacts will see you as "available" with a note that says "I'm mobile."
Some tips for using Yahoo! Messenger via text messaging:
* To initiate an IM with a friend: Text to [Friend's Yahoo! ID] [message] to 92466. For example, if your friend's Yahoo! ID is Djben05 and your message is Hello, your text should read: to Djbeno5 Hello. Leave a space between to, your friend's Yahoo! ID and your message.
* To reply to an IM from a friend: Reply directly to the SMS with your message.
* To receive information about Yahoo! Messenger via text messaging: Text help im to 92466
* To log out: Text out to 92466.