When a projet containing diagrams on several tabs is reopened, then only two tabs are restored; The last one used plus the one created first. The others can be seen if Diagram / Show / <diagram name> is clicked on. It is tedious to have to reactivate almost all tabs every time a diagram is opened.

Reproducible: Always

Steps to Reproduce:
1. Create a .cpp and .hpp file with at least 4 classes
2. Import code using "Import Code Wizard"
3. Put each class on a separate Class Diagram tab
4. Close and reopen projekt

Actual Results:  
 Notice how only the first tab and the last active tab is restored

Expected Results:  
 All diagram tabs restored

// Sample main.hpp file to import into umbrello
class A0
{
public:
  A0(void);
  ~A0(void);

  virtual void myFunc(void) = 0;
};

class B0 : A0
{
public:
  B0(void);
  ~B0(void);

  virtual void myFunc(void);
};

class C0 : B0
{
public:
  C0(void);
  ~C0(void);

  virtual void myFunc(void);
};

//////////////////////////////////////////

class A1
{
public:
  A1(void);
  ~A1(void);

  virtual void myFunc(void) = 0;
};

class B1 : A1
{
public:
  B1(void);
  ~B1(void);

  virtual void myFunc(void);
};

class C1 : B1
{
public:
  C1(void);
  ~C1(void);

  virtual void myFunc(void);

  B0 b();
};

//////////////////////////////////////////

class A2
{
public:
  A2(void);
  ~A2(void);

  virtual void myFunc(void) = 0;
};

class B2 : A2
{
public:
  B2(void);
  ~B2(void);

  virtual void myFunc(void);
};

class C2 : B2
{
public:
  C2(void);
  ~C2(void);

  virtual void myFunc(void);

  C1 c();
};

//////////////////////////////////////////

class A3
{
public:
  A3(void);
  ~A3(void);

  virtual void myFunc(void) = 0;
};

class B3 : A3
{
public:
  B3(void);
  ~B3(void);

  virtual void myFunc(void);
};

class C3 : B3
{
public:
  C3(void);
  ~C3(void);

  virtual void myFunc(void);

  B3 b();
};