GUI unstable -Anyone else having this problem?

[cnshht]

When I start Phex (WINNT4) it opens in a less-then-fullsize window, and the screen does not get fully drawn. If I then maximize this window, the GUI appears in it's full glory, with all the nice button-and-tab graphics and shading and outlines. I like it in this state; it is easy to navigate and use. However, after I work with other programs, or minimize Phex to the systray for a while, I lose this nice top layer, and I am back with the original 'skeleton', which still functions, but is hard to use. Then I can never get the nice GUI back again unless I shut down and restart Phex.
The 'skeleton' window has all functions, but lacks field outlines and shading.... Likewise text-selection becomes invisible. Mouse-active spots are reduced to faint slash-marks, and it takes some stumbling around to perform basic maneuvers.

Does anyone else have this problem? I would blame some quirk of my Machine, but I have no similar problem with any other program.