The issue is the server I run it from is Windows 2003 32-bit. When I tried to run it from our new management server, 2008 x64, or from any of the 64-bit 2003 servers, it would seem to start, then crash. I'd see the following error in the event log:
Faulting application log parser lizard.exe, version 1.0.0.0, stamp 48565da6, faulting module kernel32.dll, version 5.2.3790.4062, stamp 462643a7, debug? 0, fault address 0x000000000000dd10.
I've seen this before, actually, on our own code. Seems sometimes developers will write an app in a 32-bit environment but not explicitly set it to load 32-bit. This is generally ok since most .NET apps will run fine in 32-bit or 64-bit, but it seems LogParser Lizard includes a lot of freeware .dll's that are 32-bit only. As a result, even though the main .exe loads 64-bit, it tries to then load 32-bit only .dll's.
Fortunately this is easy to fix. If you don't already have it installed, install the Microsoft .NET 2.0 SDK. In it there's a tool called "corflags.exe" (no, there's no "e" in corflag). This is used to modify the header of a binary to set it to be explicitly 32-bit.
To do this, run:
corflags.exe c:\full\path\to\logparserlizard.exe /32BIT+
To undo it, run the same with /32BIT-
Then it runs fine :-)