First of all, refer to this document for how to ask questions:
Under what operating system are you running LiteStep? With which modem are you experiencing this problem? Are the latest vendor-supplied device drivers for your modem installed? Is it a "winmodem" (which is a modem without an integrated controller chip), a "DSP-less modem" (which is a modem without an integrated controller chip or a digital signal processor), or a "hardware modem" (a modem that includes both an integrated controller chip and a digital signal processor)? Is it connected through ISA, PCI, CNR, AMR, USB, or serial? Did you change any other settings in your operating system's configuration files prior to or shortly after having installed LiteStep? If you remove LiteStep from your system, does the problem go away?
Just from prior experience, my educated guess is that your modem is a "DSP-less modem" such as those manufactured with Conexant's "HSF" series chipsets. Some necessary applet that is included with the device drivers is either incompatible with or has been superceded by a LiteStep module.
Post back with answers to those questions, and we'll see if we can help you.