Can't see pmail GUI when not maximized (Self Solved)

I have been using Pegasus for probably has many years as the product exists.

And now experiencing a problem I never seen before and I can't resolve myself :-(

Pegasus froze during a global mailbox search (probably stuck in a IMAP folder)

After I shut it off, I can't see the GUI unless I go in Windows processes and maximize PMAIL window.

Then in Pegasus, if I try to use it not maximized. It disappear :-(

 How can I reset the GUI size and position?

 Thanks

(System is running Win8.1)

 EDIT - I managed to solve it myself

1. Must use a process/task viewer to maximize the window in order to see the GUI (I use ProcessExplorer)
   
2. Right-Click on Taskbar and select show windows side by side [does not work if (1.) is not done]
3. Then you can play with size and location of the PMAIL GUI - Close Pegasus - Reopen it... All back to normal.

 WEIRD!