The 36-year-old finished fifth in race one and seventh in race three, but crashed out of race two in Lincolnshire.
However, with rival Tarran Mackenzie not riding due to injury, Iddon moved up to second place overall in the championship standings, level on points but ahead on countback scores.
The rivals both have 223 points on the board, with leader Jason O’Halloran on 342.
“You make your own luck in this game and that’s two crashes in two meetings which have been my fault," Iddon reflected.
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"And when added to two when I was knocked off, it’s disappointing in one way. But with Taz not riding, I’ve somehow managed to climb to second in the title (race).
"In truth, we’ve chased our tail all weekend and I’ve not found a suitable setting despite the team working so hard.
"We were hoping to get some more data in race two to help for the final race, but the crash scuppered that.
"We now regroup and head to Snetterton in a positive frame of mind as that’s where I got my maiden win last year.”
The VisionTrack Ducati rider still has plenty of positives to take as the campaign reached the halfway stage.
Friday's dry conditions were replaced by damp weather initially this morning of Saturday, but it had dried in time for qualifying, where the session interrupted by a red flag due to a crash involving Friday’s pacesetter Ryan Vickers.
As a result, Iddon lined up in ninth on the grid for the afternoon’s 14-lap BikeSocial sprint around the tight and twisty 2.20-mile circuit.
The race got underway in dry conditions but early on, overtaking was hard.
Iddon latched onto the back of a five-rider battle for the final podium position and, although he couldn’t make it into the top three, he nevertheless took a strong fifth place.
“I’m quite content with today’s result and after qualifying about where our pace suggested we should be," Iddon said after Saturday's race.
"I had a much better race. I didn’t make the greatest of starts so it was hard work, but we made good strides forward and with about three to four laps to go, I thought we may be able to make it onto the podium. It wasn’t to be sadly.”
The solid result from the first race day meant Iddon started Sunday's opening race, held over the longer distance of 18 laps, from third, making a strong start on the factory-supported VisionTrack Ducati Panigale V4RR.
Lap three saw Iddon running in third, but his race didn’t last much longer as he crashed out at Charlie’s.
For the final race of the weekend, Iddon began in 12th, his tough day ending on a slightly better note with seventh-place points.
Team co-ordinator Johnny Mowatt said: “Christian’s had a bit of a tough day and he looked confident in the opening race until he tucked the front and crashed out.
"He was a long way back on the grid for the final race so with a few crashes recently he rode a bit cautiously which was to be understood."
The final round is at Snetterton from September 3-5.