I've been playing around with this, and don't know if this has any side effects, but you might try the following and see if it fixes the problem:
in inc_func_common.asp around line #378 (in the chkString function) find the following:
fString = replace(fString,"+","+")
insert the following line of code just above that line: fString = replace(fString,"""",""")
so that it now looks like this: fString = replace(fString,"""",""")
fString = replace(fString,"+","+")