Date not included in list on page 10 of Kimberley Rew's Soft Boys scrapbook, (and Kimberley does not appear to have a setlist for May 11) so could be incorrect. Potentially confused with Strawberry Fair on June 10, 1978. We don't know why there are two potential dates for Strawberry Fair this year. Per Wikipedia Strawberry Fair is typically held on the first Saturday in June.

However, punk band The Users have a gig listed on this date at Strawberry Fair, and they played a lot of the same gigs as the Soft Boys in 1978 (at Alex Wood Hall, Nashville etc) so it's plausible this gig happened even though it's missing from the Scrapbook. As of now, though, it looks like June 10 was the correct date.