I just ran into this and I have confirmed it as a bug with K2.  However, there is a work around I am writing a blog on.  Should have it done this week.

However, if you need to do something ASAP, just right click on the sharepoint integrated client event, select to veiw the code, the view the code in the WF.  At this point, I am going on my memory because I do not have my K2 machine running, however you will see some commented out code that is creating a URL.  Uncomment the code and that is a temporary solution.

I will have a better one up soon and will reply here when I get it done...

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Thank you for you quickly answer. The commented out code you refer, I think should be that in "- ExecuteForUser -" region:

// Do not remove - Can be used as another method to populate worklist
K2Uri uri = new K2Uri(GetXmlFieldValue("WebURL"));
workListURL = uri.FormatURI(true) + "_layouts/WrkStat.aspx?List={";
workListURL += listId.ToString() + "}&WorkflowInstanceID={";
workListURL += workflowInstanceId.ToString() + "}&ItemUniqueId={";
workListURL += listItemId.ToString() + "}&taskListId={";workListURL += taskListId.ToString() + "}";
workListURL = HttpUtility.HtmlEncode(workListURL);

Unfortunatly, this code doesn't open sharepoint worklist item but the sharepoint workflow status page...

I'm eargly waiting your post :-)

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