IE8, gwt-dnd 3.0.1 sporadical errors when starting drag?

[GoogleCodeExporter]

What version of GWT are you using? 1.3.3? 1.4.60? Other?
2.0.4

What version of the gwt-dnd jar file or library file are you using?
3.0.1

What operating system(s) are you using? Windows? Linux? Mac?
Windows 7 64bit

Does the issue occur in web mode, hosted mode, both or don't know?
both, but only IE (only have IE8)

What browser(s) do you use? Firefox, IE, Safari, other?
IE8; Firefox & Chrome work as expected

What is the browser version (if you know) from Help->About?
Internet Explorer 8.0.7600.16385
Mozilla Firefox 3.6.8
Google Chrome 6.0.472.55

What steps will reproduce the problem? Please attach sample code if you
can.
Start a drag? don't know exactly, will try to add info later, when i find out 
more

What is the expected output? What do you see instead?
expected: working dnd-behavior
IE8: sporadically when starting a drag, it doesn't happen, and
in hosted mode i get the error:
14:26:34.644 [ERROR] [atom_v9] Uncaught exception escaped
com.google.gwt.core.client.JavaScriptException: (Error): Ungültiges Argument.
 number: -2147024809
 description: Ungültiges Argument.
    at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:195)
    at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:120)
    at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:507)
    at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:264)
    at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91)
    at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
    at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:188)
    at sun.reflect.GeneratedMethodAccessor171.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
    at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
    at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:157)
    at com.google.gwt.dev.shell.BrowserChannel.reactToMessages(BrowserChannel.java:1669)
    at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:401)
    at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:222)
    at java.lang.Thread.run(Thread.java:619)

In web mode i get the error:
Meldung: Ungültiges Argument.
Zeile: 3089
Zeichen: 195
Code: 0
URI: 
http://10.0.1.51:8080/ATOM/atom_v9/7800CCFFE695429825814DEDCCC9E009.cache.html
the line 3089 of the file above is:
function oI(b,c,d){var a,f,g;c!=null&&X2(c.tI,76)&&RJ($8b);try{g=CI(new 
AI,c,Z2(d,77).Fb(b),Z2(d,78).Hb(b),(Z2(d,79).Gb(b),Z2(d,80).rb(b)));b.c.td(d,g)}
catch(a){a=deb(a);if(a3(a,81)){f=a;throw mH(new PG,_8b,f)}else throw a}}

Do you have a workaround?
No, please help me

Please provide any additional information below.
I would like to investigate further, but I don't know how, please tell me where 
to look, i.e. what could i have done wrong to cause IE8 to not work while 
firefox and chrome do

Original issue reported on code.google.com by kaef...@gmail.com on 9 Sep 2010 at 12:55

[GoogleCodeExporter]

I just downloaded the sources of your demo from 
http://gwt-dnd.googlecode.com/svn/trunk and compiled it with gwt 2.0.4 and 
gwt-dnd 3.0.1 and it works in my ie8 just like the one you host, so it must be 
something that i did wrong.. i will try to investigate further next week, if 
someone has an idea what it could be, please post it

Original comment by kaef...@gmail.com on 9 Sep 2010 at 1:29

[GoogleCodeExporter]

Okey, so I found out my mistake, In my DragController I overwrote 
newDragProxy(DragContext context) and in there I have set paddingLeft of my 
Proxy Label sometimes to a negative value. Firefox and Chrome dont mind 
negative values there, IE8 throws around javascript errors.

More interessting for me was the way I found out: compile the application with 
"-style DETAILED" and then look at the line of the javascript file that throws 
the error.

ps.: please close the bug mark it invalid or something like that.

Original comment by kaef...@gmail.com on 16 Sep 2010 at 9:17

[GoogleCodeExporter]

Thanks!

Original comment by fredsa@google.com on 22 Sep 2010 at 7:24

• Changed state: Verified

[GoogleCodeExporter]

I have to thank you for the great library, and its not like I found a bug in 
it, I only documented my mistakes while using it.

Original comment by kaef...@gmail.com on 22 Sep 2010 at 7:40

[GoogleCodeExporter]

Thanks

Original comment by fredsa@google.com on 29 Sep 2010 at 5:21

• Changed state: Invalid