NullReferenceException generated when td rowspan=2 in tooltip

Hello,

when adding a tooltip to any object with tooltip text containing "rowspan" tag, like this: 

Dim tip = "<table><tr><td rowspan=2>text1</td><td>text2</td></tr><tr><td>text3</td></tr></table>"

Me.C1SuperTooltip1.SetToolTip(Button1, tip)

the NullReferenceException generated

This problem comes with v.2008.2 and v.2008.3 releases (C1.Win.C1SuperTooltip.2.dll 2.0.20083.56). The older dll (2.0.20073.44) works well.

Thanks,

Vladimir