I have this modem. Go to
http://downloadfinder.intel.com/scri...7&DwnldID=8023 for the uncompiled driver. It's for MDK 10.1, but since you have to compile it yourself, it *should* adapt itself to your system. Just unpack the files, go to the directory for the driver, and type
make clean
make 536 (or 536ep... can't remember which one this version requires)
if all goes well with no fatal errors, type
make install
Presto, you can now configure your connection (if you haven't done so already) and get online. If there are any problems, you can always go to google, (or I prefer linux.google.com) and do a search for "Intel 536ep modem on Mandrake 8.2". I'm sure there's an archive out there with the backdated driver. If you need to do this, you can follow the same instructions or follow the readme included in the file.
Be sure to post how it turns out.
Although, I strongly agree with sgrayban that you should definitely upgrade.