I have this happen twice so far, not sure why. Here the events

first off  SWISH-E is running on a win2k server.

The Events. I index a lager number of files about 7 Gb of text files
after indexing is done, whenever I go and do a search I receive the following exception error popup

 swish-search.exe - Application Error : The instruction at "0x000001f4" referenced memory at 
 "0x000001f4". The memory could not be "read".

Click on OK to terminate the program
Click on CANCEL to debug the program

to fix the problem I uninstall SWISH-E and then reinstall
while reinstalling  I receive this error from the install program 

zlib.dll can not be replaced | abort | retry | Cancel

I abort from the install and go and move the zlib.dll from the system32 folder to some other 
folder and then I reinstall and everything starts working again.

I do not understand why this is happen this way.. is zlib.dll that flaky?