negative solar radiation

[Jeroen Van der Veken <Jeroen.VanderVeken@xxxxxxxxxxxxxxxxxx>]

Hello collegues,
I'm running some simulations on a heating system in a residential 
building. The heat is produced by type6 and delivered into the zones of 
type56 by radiators based on type182, coupled with type80. But I'm 
experiencing some ennoying TRNSYS problems.
If the timestep is high (say 0.2 hours), the type56 building produces 
pane temperatures that are out of bound. This could be logical when 
there is too much (radiation) energy delivered in one timestep.
That is no problem anymore if I lower the timestep to 0.1 hour and less, 
and/or reduce the power of the radiation. However, with smaller 
timesteps I get the error
***** ERROR *****        UNIT  20 TYP # 56
NEGATIVE VALUE OF SOLAR RADIATION FOR  5. ORIENTATION ENCOUNTERED. 
SIMULATION STOPPED.
If I follow the radiation from the radiation processor, this doesn't 
seem the case. It seems that the problem is in Type56.
And to make it really frustrating, TRNSYS doesn't appear to like my 
TPF-files and announces from time to time when I want to save the 
project "save failed". Trying to save it on another disk or diskette 
doesn't work and when I reboot my computer, the whole file seems to have 
dissapeared from the hard disk. Not only the latest changes, the whole 
thing.

Hopefully somebody can help to make work less frustrating :)
best regards,
Jeroen