I think I need more information on what values you entered because I tested it and it appeared to calculate the reserve fee correctly.
We do seperate the "insertion fee" from the "reserve fee" though since eBay refunds the reserve fee portion if your item sells.
With a Start Price of $1 and a Reserve of $242.55:
Estimated eBay fees to list this auction are broken down as follows:
Insertion: $0.35
Reserve (refunded if item sells): $2.43
Total*: $2.78
Thanks,
Auctiva David