I beleieve the assembly size is less than 640 K.
You said "Often when compiling I get ", does this mean it works sometimes and sometimes not?
Do you have an antivirus program that uses real-time scanning?
If yes, please try to stop real time scanning and try again.
Would you give us more hints about your setup?
Windows version, Target Database.
Do you set CopyLocal to true, when referencing the assembly in your VS solution?