SRDF thick to thin (or vice versa) was not supported until a later version of SE than 7.1. Upgrading Solutions Enabler should solve the SRDF command issue.
We have a SRDF group which has all thick devices.We recently added few thin devices to the same group. Now group is behaving weird .Not able to get all devices in split state.  Below is the symrdf query output         Source (R1) View                 Target (R2) View     MODES --------------------------------    ------------------------ ----- ------------              ST                  LI      ST BCV           A                   N       A Logical       T  R1 Inv   R2 Inv  K       T  R1 Inv   R2 Inv       RDF Pair Device  Dev   E  Tracks   Tracks  S Dev   E  Tracks   Tracks MDAE  STATE -------------------------------- -- ------------------------ ----- ------------   BCV001  0126 RW       0        0 NR 005F RW       0        0 S...  Split BCV002  06E1 RW       0        0 NR 0461 RW       0        0 S...  Split BCV003  014A RW       0        0 NR 046D RW       0        0 S...  Split BCV004  012C RW       0        0 NR 0065 RW       0        0 S...  Split BCV005  0132 RW       0        0 NR 006B RW       0        0 S...  Split BCV006  0138 RW       0        0 NR 0071 RW       0        0 S...  Split BCV007  013E RW       0        0 NR 0077 RW       0        0 S...  Split BCV008  0144 RW       0        0 NR 007D RW       0        0 S...  Split BCV009  29BE RW       0        0 NR 0486 RW       0        0 S...  Failed Over BCV010  29BF RW       0        0 NR 0492 RW       0        0 S...  Failed Over BCV011  29CB RW       0        0 NR 049E RW       0        0 S...  Failed Over BCV012  29D7 RW       0        0 NR 04AA RW       0        0 S...  Failed Over BCV013  29E3 RW       0        0 NR 04B6 RW       0        0 S...  Failed Over BCV014  29EF RW       0        0 NR 04C2 RW       0        0 S...  Failed Over BCV015  29FB RW       0        0 NR 04CE RW       0        0 S...  Failed Over BCV016  2A07 RW       0        0 NR 04DA RW       0        0 S...  Failed Over    'split' devices are thick devs and 'Failed over' devices are thin devs  this is because rdfg 57 has holding both Thick and thin ?
Thick and thin devices together in SRDF group.