in my experience, using Telkom ADSL (1024) at our office, I can expect at least one disconnect per morning (when I use it). Some days are worse, some are better. On the whole, it seems to be better the last month, but I have not been using it as heavily. When it drops, the entire ADSL connection drops for 10 seconds to a couple of mins.
First thing you should check is that you have everything up to date, all software, firmware, etc. get the latest version of Skype, Windows service packs, even your router, BIOS, LAN etc...
second check your line quality, does the line drop when someone calls in? upgrade your POTS filters if you are using ADSL. how is the general line quality in your area?
at least one drop a day is to be expected most days... that seems par for the course... some days you might get five or more drops. If it is happening every two minutes thought... then there is something more serious wrong.