Limitatin in GParted on a stick?

I have a system as follows (printout from fdisk -lu):
Device Boot      Start         End      Blocks   Id  System
/dev/sda1              63     8385929     4192933+   5  Extended
/dev/sda2   *    15631245    44933804    14651280   83  Linux
/dev/sda3        44933805   488392064   221729130   83  Linux
/dev/sda5             126     8385929     4192902   82  Linux swap / Solaris
I have managed to shrink da5, which is peculiarly situated inside sda1, and sda1 creating an unallocated 3,45 GB large empty space (not visible in the table).  Since sda2, which contains my root partition, is nearly full (98 %) I would like to to increase it by expand it into the nearby unallocated space. This does not work and GParted terminates with a fault. Is there a limitation when resizing almost full partitions from an USB-stick?
If not, what might be wrong? Grateful for any hints.

Sven