Also if you're using MoI version 2, make sure you're using the "update 2" version of that command which is this one:
http://kyticka.webzdarma.cz/3d/moi/cc/importpointfile/ImportPointFile_Update2.zip

The original one won't work on Windows Vista or Windows 7, and the last one mentioned only works on the OSX version of MoI, so if you're using either one of those that could be the problem.

- Michael