I also had tried an IRD cassette and was never able to get it to work well enough to ride on.
What I did was to return the IRD and then I got a Shimano Ultegra 12-27 and then ordered a single 30 tooth cog from Harris Cyclery and threw out the 12 cog ending up with 13-30 9 speed cassette. Harris Cyclery also sells complete cassettes in various combinations, but it is a little less expensive to buy the cassette and individual cogs and change it yourself. I have bar end shifters and this combination works very well. Using Shimano cable housing could not hurt although it may not help either. The fact is that 100% Shimano systems work well and when you deviate problems can result.