It appears to be the HATA (Hawaii, Alaska, Territories. APO/FPO) search/visibility bug as others mentioned.
Hawaii has been hit or miss when it comes to its effects, whereas an Alaska pr Puerto Rico zipcode always seems (seemed?) to cause listings and store items to go invisible.
Something changed somewhat in the last few months. Used to be that if a zipcode caused listings to disappear it was in search and in the store.
Now, at least when I use zip 96801 (Honolulu), I still see 273 results for you in search, but only 7 items in your store. Same if I use an APO/FPO zip like 09012. If I change to 99514 for Anchorage, AK, I only see 13 items in search and same 7 items in your store. If I change to Puerto Rico 00785, I see 12 results in search, and your store really whacks out with ZERO store results.
All that doesn't help you though, and unfortunately, there is nothing to be done except hope eBay gets it fixed. And change your zipcode to 90210 (or whatever on the mainland like 10012 in New York) for poking around in your store or looking for your items in search.
Realize that it only affects buyers/viewers in HATA zipcodes - 98% of the US population can see your items and it's only the few in Alaska, Territories, APO/FPO, and some sometimes in Hawaiian zips that don't see them.
As far as the issue when signed out goes: when signed out, I believe eBay guesses at your location based on geolocation, and is probably placing you in Hawaii, but the process is blowing up. That is a new twist, and I have no ideas on that (trying to think of testing methods to see if anything can be divined, but tough to move my location about without VPNs with IPs in specific locations that I don't have access to, and not sure are something that would cause eBay to believe I'm in a specific place anyway)
