The "Tribes of the East" campaign in Heroes 5 freezes.

Computer configuration: Athlon 5000+ EE, 1GB (2x512) DDR2 800, integrated Nvidia 6150 video, Samsung 250GB hard drive, S250 series. Windows XP SP2, installed a week ago. I bought a licensed copy of Heroes 5: Tribes of the East. The game freezes during the campaign in the Heart of Darkness mission. After the cutscene with the ghost of the governor of the Holyflame city, the game completely freezes (the mouse turns into a loading cursor, and almost nothing works in the game on the screen). I exit to Windows and terminate the program, reload... and it happens again. At first, I thought the game was installed incorrectly... I reinstalled it... but it didn't help. Then, I downloaded all available patches, installed the original version, and applied the patches... no reaction. Then I thought that there wasn't enough video memory (I had 128MB allocated). I allocated 256MB from the RAM for the video core (there was almost 900MB of RAM, and now there are 768MB), but if there isn't enough RAM, then the swap file will be used (it reserves space on the hard drive and loads it when needed). I only have 3 options left: a) the game itself was poorly written (but then others would have the same problem) b) I got a bad disc (unlikely - it's a licensed disc, I bought it at Sunrise) c) software and hardware incompatibility (unlikely, because the hardware is quite good, with all the latest updates, including the BIOS). I generally don't have the habit of buying "bad" hardware. I don't have a dedicated video card because I don't play games (except for Heroes 5:smile44:). In general, I don't know what to think! :confused: Please help - maybe someone has encountered the same problem? Or maybe someone just knows where the problem lies. Thank you in advance for your valuable advice.