Sounds pretty hot to me LOL.

If the additional cooling has resolved the freezing problem I think you've found your answer.

I assume you've had the case off and a normal room fan blowing on the card which isn't practical (or advisable) for long term use.

Try installing a case fan at each end of your case, one sucking in and one blowing out. this should significantly increase the flow of air and would hopefully produce similarly effective results.