Yip, exactly the same symptoms here on Afrihost 4Mbps. Local has been at around 1-2Mbps and international at 0.2 - 0.5Mbps for the best part of the last week. Very rarely and only for short bursts, the international works at around 1Mbps, but for the most part it's been consistently < 0.5Mbps. Their support guys say I'm definitely not throttled, as I have only downloaded about 8GB this month.
They've also checked some logs their side and apparently my line is resyncing sporadically, so that might explain the local issue - something I need to take up with Telkom when I've got time to sit on hold...
But, it doesn't explain the shoddy international performance. I usually get the 0.2Mbps international when the local is flying (not at exactly the same time, one test immediately after the other).
The worst part of it all, is I explain the symptoms precisely to the Afrihost support guys and all I get back from them is the "your line is the problem contact Telkom" line.
There may well be a problem with my line... However, that's certainly not the _only_ problem. There's something pear shaped their side too (and according to this forum I'm not the only user seeing this).