I've noticed many of hashbuster users seem to have cooling issues, i used an old hp opteron heatsink some thermal material and a lot of thermal grease. It's only been up 11hrs but seems very stable temp wise;
http://imgur.com/sgf0DkLbfgminer version 3.8.1 - Started: [2013-12-09 19:12:10] - [ 0 days 11:05:00]
[M]anage devices [P]ool management S]ettings [D]isplay options [H]elp [Q]uit
Connected to stratum.eligius.st diff 64 with stratum as user 1A2UmpbSt8wF3t2wyeMB5t
Block: ...60460e4f #274112 Diff:707M ( 5.06Ph/s) Started: [06:16:16]
ST:9 F:0 NB:100 AS:0 BW:[153/ 29 B/s] E:62.81 I: 715uBTC/hr BS:597k
1/9 30.0C | 24.86/24.81/24.13Gh/s | A:7366 R:22+0(.31%) HW:4506/2.0%
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HBR 0: 30.0C | 25.04/24.81/24.13Gh/s | A:7366 R:22+0(.31%) HW:4506/2.0%
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[2013-12-10 06:14:24] Accepted 000cbc11 HBR 0d Diff 5.15k/32
[2013-12-10 06:14:24] Stratum from pool 0 requested work update
[2013-12-10 06:14:26] Stratum from pool 0 detected new block
[2013-12-10 06:14:31] Stratum from pool 0 requested work update
[2013-12-10 06:14:34] Accepted 007cddaf HBR 0g Diff 524/64
[2013-12-10 06:14:38] Accepted 00ba5677 HBR 0i Diff 351/64
[2013-12-10 06:14:48] Accepted 010f3111 HBR 0f Diff 241/64
[2013-12-10 06:14:58] Accepted 03303cc1 HBR 0d Diff 80/64
[2013-12-10 06:14:59] Accepted 016feeb0 HBR 0d Diff 178/64
[2013-12-10 06:15:18] Accepted 00eee21e HBR 0c Diff 274/64
[2013-12-10 06:15:26] Stratum from pool 0 requested work update
[2013-12-10 06:15:28] Accepted 028d689a HBR 0c Diff 100/64
[2013-12-10 06:15:59] Accepted 03d9e0f8 HBR 0d Diff 66/64
[2013-12-10 06:16:10] Accepted 02eb994f HBR 0f Diff 87/64
[2013-12-10 06:16:16] Stratum from pool 0 detected new block
[2013-12-10 06:16:18] Stratum from pool 0 requested work update
[2013-12-10 06:16:26] Accepted 02bb180f HBR 0d Diff 93/64
[2013-12-10 06:16:43] Accepted 01ab72bf HBR 0b Diff 153/64
thanks hashbuster