When you write "power steering belt blew off my car," what do you mean? Did the belt break, or did it roll off?
I ask because there were problems with Chrysler's design of the power steering pump bracket, and the tensioning pulley. Mitsubishi published a coupla of technical service bulletins (TSB), presumably using service information from Chrysler, that specified the use of 1 mm shims to better align the power steering (and A-C, if it's installed) serpentine accessory belt with the tensioning pulley. A new, wider tensioning pulley and redesigned power steering pump bracket were introduced and described in the TSB. The Mr. Bishi TSB ID is 98-37A-005, which supercedes the earlier TSB 97-37A-001 on the same topic.
If your '98 RS was an early model-year build at the Normal, IL factory, you might not have the redesigned parts, as the TSB specifies that the new parts were assembled on vehicles built after 2 February 1998. Your car is out of warranty, so you'll hafta pay for the parts and installation work; not likely that you can convince your local Mr. Bishi dealer to do the work for free. Check your car's build sticker on the door jamb to determine when it was assembled. If you're gonna have another shop do the work for you, give 'em the TSB ID, so that they fix the problem correctly. The new bracket and tensioning pulley may cost as much as $250 from the local dealer, and it'll take coupla hours labor to remove and replace the parts. There isn't much room under the Eclipse's hood, so working on the engine can be more time-consuming, depending on the repair procedure.
Correct serpentine belt tension is also critical; the specified tension range in the TSB is 93-115 lbf.
The OC, SoCal, USA.