Thank you all for your suggestions. I tried "18" and I have got the following readings which is a whole lot better than where I started first at.
cgminer version 3.7.2 - Started: [2014-02-01 21:39:06]
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(5s):309.5K (avg):416.0Kh/s | A:32 R:0 HW:169 WU:30.7/m
ST: 2 SS: 0 NB: 1 LW: 13 GF: 0 RF: 0
Connected to stratum2.dogechain.info diff 15 with stratum as user ClueLez.xx
Block: feb1f082... Diff:1.4K Started: [21:39:06] Best share: 39
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Pool management GPU management Settings Display options Quit
GPU 0: 52.0C 1177RPM | 448.2K/416.0Kh/s | A:32 R:0 HW:169 WU:30.7/m I:18
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[2014-02-01 21:39:02] Started cgminer 3.7.2
[2014-02-01 21:39:02] Loaded configuration file cgminer.conf
[2014-02-01 21:39:02] Probing for an alive pool
[2014-02-01 21:39:06] Pool 0 difficulty changed to 32
[2014-02-01 21:39:06] Network diff set to 1.4K
[2014-02-01 21:39:14] Pool 0 difficulty changed to 15
[2014-02-01 21:39:14] Stratum from pool 0 requested work restart
[2014-02-01 21:39:14] Accepted 069dec79 Diff 39/32 GPU 0
Hi Scriptio,
Apparently the -I 18 is slightly too high for your 280, so you can tune it: reduce it by 1 until you see that the HW:0 does not go up any more.
I also see that your GPU is running very cool (52 deg C) so once you are done tuning for the optimum Intensity (probably around 15) and you see the WU numbers go in the hundreds instead of a paltry 30/min, then you can start Overclocking if you want to get the maximum hash rate from your card and you do not mind it using more power and having a louder fan.
Success!