VETKA.COM spoils itself after the first use

[GoogleCodeExporter]

Depending on the initial state of startup disk, it may create a new hiscore
table, or find/use existing one. Apparently, some clash in fdd emulation
causes code corruption in the game file itself. When run for the second
time, VETKA.COM would start in super-complex mode, attempt to enter
Keyboard menu will hang. 

Brief examination shows that memory area around address $2800 is zeroed,
instead of having meaningful code which can be observed if VETKA.COM runs
properly.

Original issue reported on code.google.com by svof...@gmail.com on 29 Aug 2008 at 10:06