Issue when analysing assembly with contact+large deformation

I'm starting to use CREO simulate 2.0 because of its ability to analyse assemblies with both contacts and large deformation (I'm still designing my parts and assemblies with WF5).

Unfortunately, ##############I'm stuck in a "Decomp. Singular Stiffness Matrix. Recovering..." kind of loop (an analysis can run a couple of hours instead of a few minutes).

The assembly and analysis definitions were made in WF5 and opened/run with creo simulate 2.0.

Does anyone already have this kind of issue and know how I could get rid of it ?

Thanks !

PS: Here is an extract of my *.pas file:

 

Begin Time Step 1 of 4:  2.50000e-01
Wed May 22, 2013   15:01:24
Contact Analysis detected large displacements at one or more contact regions
This can be caused by a very flexible model or disconnected volumes or components
Temporarily overriding load factor with: 0.025

Iteration     Residual norm    contact Area
------------- ------------- ---------------
            1       1.06435 35.9305     Wed May 22, 2013 15:02:26
            2      0.182749 36.4971     Wed May 22, 2013 15:02:47
            3      0.103263 37.8594     Wed May 22, 2013 15:03:08
            4     0.0193484 34.3545     Wed May 22, 2013 15:03:24
            5   0.000323151 34.4427     Wed May 22, 2013 15:03:45
            6   0.000297367 34.2831     Wed May 22, 2013 15:04:06
            7   0.000204668 34.1412     Wed May 22, 2013 15:04:27
            8   0.000163927 34.036     Wed May 22, 2013 15:04:48
            9  7.18929e-005 33.7046     Wed May 22, 2013 15:05:09
reset load factor to: 0.25
           10             1 37.0183     Wed May 22, 2013 15:05:31
           11       0.36423 34.3194     Wed May 22, 2013 15:05:47
*** Decomp. Singular Stiffness Matrix. Recovering...
           12    0.00323441 34.0553     Wed May 22, 2013 15:06:21
*** Decomp. Singular Stiffness Matrix. Recovering...
           13   0.000716325 33.9881     Wed May 22, 2013 15:06:55
*** Decomp. Singular Stiffness Matrix. Recovering...
           14   0.000290376 34.0191     Wed May 22, 2013 15:07:28
*** Decomp. Singular Stiffness Matrix. Recovering...
           15     0.0001727 34.0617     Wed May 22, 2013 15:08:13
*** Decomp. Singular Stiffness Matrix. Recovering...
           16   0.000121401 34.0466     Wed May 22, 2013 15:08:59
*** Decomp. Singular Stiffness Matrix. Recovering...
           17  9.55203e-005 34.0458     Wed May 22, 2013 15:09:44
*** Decomp. Singular Stiffness Matrix. Recovering...
           18   7.8602e-005 34.0241     Wed May 22, 2013 15:10:29
*** Decomp. Singular Stiffness Matrix. Recovering...
           19  6.67756e-005 34.0632     Wed May 22, 2013 15:11:15
*** Decomp. Singular Stiffness Matrix. Recovering...
           20  5.74682e-005 34.0643     Wed May 22, 2013 15:12:00
*** Decomp. Singular Stiffness Matrix. Recovering...
           21  5.01283e-005 34.0688     Wed May 22, 2013 15:12:46
*** Decomp. Singular Stiffness Matrix. Recovering...
           22  4.41229e-005 34.0759     Wed May 22, 2013 15:13:31
Adjusted gap stiffness to prevent interpenetration
*** Decomp. Singular Stiffness Matrix. Recovering...