Definitely call Donna at the home office and she can take care of you...she's really good at what she does and it should be better than having another hassle at the track.
Here is a link for the event flyer:
http://ihra.com/results/2007/proam/ads/maryland.pdf
& here is a link for IHRA membership:
http://ihra.com/membership/index.html
Hope this helps.
See ya there!