The "one a day" is a gross exaggeration, as was the other unflattering appelations hung on an underappreciated aircraft (WidowMaker, Flying Prostitute, Baltimore Whore, etc etc).
As Rob said there were less than 50 crashes total in Tampa in B-26's. ( I think, I have copies of the records so will have to look).
The main reasons for the spate of Marauder wrecks were: improper operation and maintenance, (which resulted from) and poor training procedures.
As noted, the Curtiss Electric props were an issue. They went into flat pitch, which caused an engine overspeed immediately. This usually happened at the most critical time, on the takeoff roll, when the pilot was right around the "single engine safety speed". This happened because the Curtiss prop used a stepper motor to hold the blades in postion. If electrical power was removed from the motor, it would not be able to hold the blades in position against the torque and gyroscopic loads imposed at takeoff power. Pilots had not been trained to use the "putt putt" APU to start, taxi, and run-up the B-26, and would use battery power for these regimes. Unfortunately, at the low engine RPMs, the generators could not keep up with the electrical loads being consumed, and runaway props happened as the ships batterys went flat.
The Curtiss props were, and still are in my opinion a very GOOD prop. However, the maintenance needs are much higher than on Hydromatic props. Things such as keeping brush blocks and contacter rings free of corrosion and the attendant voltage drops/high resistance were very critical to keeping Curtiss props in good operating order.
The other major issue, and again this is rooted in training, was the high wing loading of the Marauder. The high wing loading made for a fast bomber with good capacity, but the tradeoff is highly increased landing speeds. Marauders came over the fence at 150-165, and as I recall dirty stall is around 125 (Have to go read my manuals again to be sure). So, the approach speed was higher than the cruise of some of the trainers these guys had been flying right before getting into the Marauder.
A good friend who flew Flak-Bait (Sherm Best) told me this: The Marauder was a great plane, brought him and many friends home safely with damage that was unbeliveably bad (which would have doomed a Mitchell),
but she was utterly unforgiving of a lack of skill, or attention to details. It's also germane to note that there was never a "prototype" as such. The USAAC bought the Marauder right off the drawing boards, and they and Glenn L. Martin Co upgraded as necessary on the production line.
Jimmy Doolittle did much to keep the Marauder flying, as many might know. Truman had set up an investigative committee three times about the Marauder's alleged problems. Again, this was a "Hot-Rod" plane, and was very very different from anything these airmen had flown in past. Interestingly, I was privileged to know a WASP who had over 1,000 hours ferrying Marauders from Middle River MD all over the country. She loved them, and never had any issues with the planes. Really blew some male pilots minds when this "Killer plane" would land, and a lil slip of a *girl* would wave at them from the left seat!
At the end of the war the Marauder had the lowest loss record in the entire ETO, less than 1/2 of one percent. Sadly though, her reputation as a killer doomed her, and she was stricken from the inventory, and as a final insult, in 1948 when the USAF dropped the "attack" designation, the Douglas Invader b]A-26[/b] was given the Marauder's designation. Hence, my somewhat testy reply to people "Douglas made the A-26, MARTIN made the B-26, and I don't care WHAT the USAF had to say about it!"
As you might suspect from my sig line, I have a slight interest in this plane.

Sorry for the lengthy reply... It's still a little sad that of over 5500 built, there are only 7 left (only one of which is anything close to airworthiness, Hi Kermit!!), plus about a dozen wrecks known.