UpdatePanel + IE 5.5

Are there any known problems with running UpdatePanels under IE5.5?

I have simple .aspx with updatepanel and IE5.5 craches... craches with syntax error on line 3-4 of aspx file. It also shown me "unknown error" few times.

Tried some debugging and found something about xmlhttprequest which was null, but don't know if it was the cause or the result of that issue.

Is it known issue, or updatepanel is not for ie5.5 :). the most strange thing is that i can't find in... google any usefull info about "atlas updatepanel ie 5.5"

PS. I took my atlas assembly from the latest atlas control toolkit downloaded from codeplex project site.

ok...hmm... not ok, but got something more from debugging.

in onReadyStateChange() (about line 1592 of AtlasRuntime.js) when_xmlHttpRequest.readyState == 4
_xmlHttpRequest.status = 12019 and statusText = "Unknown"...
And then it can't get msxml for some reason...

if someone had that problem please share experience :)

I'm digging deeper...