Description of Problem:

I have the following function to remove a particular character from a string 

public static string Remove(this string strA, char target) 
{ 
        char[] charArr = strA.ToCharArray(); 
        var targetArr = new List<char>();	
        targetArr.AddRange( 
                        charArr.Where( 
                            character => !character.ToString(CultureInfo.InvariantCulture).Equals( 
                                target.ToString(CultureInfo.InvariantCulture), 
                                StringComparison.InvariantCultureIgnoreCase))); 
        return new string(targetArr.ToArray()); 
} 

using this function in .Net framework gives rise to 

"Hello World".Remove('l')  ---> Heo Word

but Mono throws the following exception 

System.InvalidProgramException: Invalid IL code in (wrapper delegate-invoke) System.Func`2<char, bool>:invoke_bool__this___char (char): IL_004d: castclass 0x00000007 



  at System.Linq.Enumerable+<CreateWhereIterator>c__Iterator1D`1[System.Char].MoveNext () [0x00059] in C:\cygwin\tmp\monobuild\build\BUILD\mono-2.6.7\mcs\class\System.Core\System.Linq\Enumerable.cs:2305 

  at System.Collections.Generic.List`1[System.Char].AddEnumerable (IEnumerable`1 enumerable) [0x0001a] in C:\cygwin\tmp\monobuild\build\BUILD\mono-2.6.7\mcs\class\corlib\System.Collections.Generic\List.cs:125 

  at System.Collections.Generic.List`1[System.Char].AddRange (IEnumerable`1 collection) [0x00020] in C:\cygwin\tmp\monobuild\build\BUILD\mono-2.6.7\mcs\class\corlib\System.Collections.Generic\List.cs:139 

  at AbstractClass.Extensions.StringExtensions.Remove (System.String strA, Char target) [0x000de] in C:\Docs\Quasar\Quasar.Core\Extensions\StringExtensions.cs:263 

  at QuasarDemo.Tests.ExtensionTest.RunStringTest () [0x00000] in <filename unknown>:0 

  at QuasarDemo.Tests.ExtensionTest.Run () [0x00000] in <filename unknown>:0 

  at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (object,object[],System.Exception&) 

  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x000d0] in C:\cygwin\tmp\monobuild\build\BUILD\mono-2.6.7\mcs\class\corlib\System.Reflection\MonoMethod.cs:213 

Steps to reproduce the problem:
1. Compile the afore-mentioned function on Mono 2.6.7 and run it in Windows XP


Actual Results:
Calling the function is throwing the following exception

System.InvalidProgramException: Invalid IL code in (wrapper delegate-invoke) System.Func`2<char, bool>:invoke_bool__this___char (char): IL_004d: castclass 0x00000007

Expected Results:
The function should produce the following result as like .net framework

"Hello World".Remove('l')  ---> Heo Word

How often does this happen? 
Every time I compile and run the above code in Mono 2.6.7

Additional Information: