It seems like there are some problems with the WhiteBoard scrolling and scaling.
I am able to reproduce this on the same desktop with two OpenMeetings in the different browser windows.
Here are the steps to reproduce:
Issue 1. ========
1. Login into OpenMeetings from two browsers on the same desktop, say, from Mozilla FF and Google Chrome.
2. In Google Chrome create a WhiteBoard. Minimize chat and actions panels. Draw and write on WhiteBoard.
3. Go to FireFox; maximaze chat panel or just resize browser window. Observe WhiteBoard.
Result: All the picture from Google Chrome does not fit into FireFox WhiteBoard.
4. Go back to Google Chrome and observe the WhiteBoard.
Result: Additional empty space appears at the bottom unexpectedly.
5. Click the WhiteBoard in Google Chrome.
Result: Image on WjiteBoard returns back and now it looks as on the step 2.
Issue 2. ========
Just try to scale the WhiteBoard several time.
As a result, scrolling does not wark as expected and sometime not all the image is available on the whiteboard.