if you are using a modem. im assuming you mean a 56k modem installed in a pci slot in ur computer. you might want to invest in a faster medium of internet connection such as cable or dsl. also u will need an ethernet adapter. im pretty sure you already know this lol. but i cant be sure
now since those old school modems do in fact often share the same interrupt requests (IRQ) and system resources, the two drivers maybe conflicting and the sound card could cut off your internet connectino. say when you transmit voice, this activates you sound card....and causes the interuption. if u have any IRQ's left which you probably do, you may want to go into your cmos or BIOS setup when you boot ur computer and assign different IRQ's for the two devices. you can also do this from the device manager. the device manager is found by right clicking the my computer icon and going into properties. then the hardware tab.
once you assign the differetn system resources. check in the device manager to see if there are any conflicting resources. this can cause problems like the one you are experiencing now. test aces high and if the problem persists it may not be a problem with ur modem. this is hard for me to imagine it being anything else when it only happens after you use VOX.
it could also have something to do with ur modem not being able the amount of data fast enough to keep a connection with HT servers. i dougbt this but it might be possible lol. say u send packets to AH server to stay connected and then u suddenly send all of your modems resources to send your VOX message and none to AH. but like i said this seems like bogus because in order to send the Damn VOX message you have to be connected to AH servers in the first place. So anywho. i would try re assigning your system resources (mainly your sound card and modem) obviously making sure they use different resources.) and if this doesnt work reply in the thread and ill check up in a day or tewo see if it does anything or not.. oh and u might want to see if you have all of your drivers installed. this will also be displayed in the device manager