Currently, the following problems are known to the developers of F-PROT: #1 Problem running F-PROT on some IBM ThinkPad models. Some users of IBM ThinkPad machines have experienced a total failure of F-PROT (DOS version) to run on their machines. The reason is the following: We use the CauseWay DOS extender program to create the DOS version. The ThinkPad models in question run some programs from SystemSoft, including one named CARDXTND.SYS, which uses an old 16-bit DOS extender from Rational, which is simply not compatible with applications made with other DOS extenders. In effect, while CARDXTND.SYS is running, no CauseWay application (or for that matter, application using other extenders) can be run, not even a simple "Hello World" program. There is nothing we can do to fix the problem, and we consider it entirely the fault of SystemSoft - however, they have not yet (as of Aug. 5th, 1998) responded to our E-mails regarding this issue. Until Systemsoft fixes the problem, CARDXTND.SYS must be disabled in order to run F-PROT on those machines. #2 Problem when running F-PROT under NT. When F-PROT is used to scan a huge number of files, such as a virus collection with 130.000 infected files (which is the real-life situation where this problem was first encountered), it may exit before finishing the entire directory tree. We believe we may just have found the reason for this problem, which affects not only F-PROT but also some other DOS scanners, but as the potential reason was only found the same day version 3.03 was released, a fix has not been implemented yet.