I myself am unable to play the current GOG version as it is missing much of the text that goes in the game as well as many other things like pictures etc... So it is not fully Vista Compatible version and I am still waiting to hear from GOG if they are going to fix it. It seems to work for Windows 7 and XP but beware if you own Vista SP2 it may not work like my game so if you own Vista wait until they get it fixed before you buy it.

I don't have Panzer General 3D but . . . since no one has responded . . .
Several things come into play when a game doesn't run properly. . . . if you are using Win 7 or Vista, 32 or 64 . . . I would ask the following questions of you . . . not necessarily in this order.
Is it a desktop, laptop or netbook?
What CPU are you running? If it is AMD, did you try installing the AMD Dual Core Optimizer?
Are your video drivers the latest release? What brand is your video card? Is it a card or an integrated graphics card?
Did you ALT-Tab out of the game and check if your firewall is asking for permissions behind the game screen?
Did you install as an administrator?
Did you turn UAC off when you installed the game.
Did you try uninstalling and reinstalling in a directory outside of Program Files?
Did you right click the game shortcut, left click Properties, click the Compatibility tab and check mark "Run this program as an administrator"?
Did you try different compatibility modes?
Did you try setting affinity to a single core?
How much memory do you have? Did you try limiting the memory available to the game?
I'm asking questions that I normally would ask when trying to solve a game problem. It may be the game but eliminating the many possibilities for a graphics problem takes some time. Since you seem to have a good image but with no text overlay it may be the game is not getting full access to your hardware or game files . . . on that particular computer. . . =)
Edit: I see you posted in the game forum. If you will answer some of the questions above I will be glad to see if we can find a solution to this problem. I will monitor the game forum for your post . . . =)

All that has been checked and I sent my dxdiag to GOG so now Its just waiting to see if they get a fix for it.
Operating System: Windows Vista™ Home Premium (6.0, Build 6002) Service Pack 2 (6002.vistasp2_gdr.100218-0019)
Processor: AMD Athlon(tm) 64 X2 Dual Core Processor 5600+ (2 CPUs), ~2.9GHz
Memory: 2942MB RAM
DirectX Version: DirectX 11
GFX Card: ATI Radeon HD 4670 Series 1GB ram

Ok, sorry I couldn't help, hope you resolve the problem soon . . . =)

Ok Figured it out it was the ATI Catalyst Control Center setting. I had it on Optimal quality and that was the problem I turned it down to Balanced or or high performance and it works just fine.