Squid server "File size limit reached"

When I start my squid proxy server (debian) I get this:

2013/02/07 12:17:57| Starting Squid Cache version 2.6.STABLE18 for i686-pc-linux-gnu...
2013/02/07 12:17:57| Process ID 4526
2013/02/07 12:17:57| With 1024 file descriptors available
2013/02/07 12:17:57| Using epoll for the IO loop
2013/02/07 12:17:57| Performing DNS Tests...
2013/02/07 12:17:57| Successful DNS name lookup tests...
2013/02/07 12:17:57| DNS Socket created at 0.0.0.0, port 32800, FD 6
2013/02/07 12:17:57| Adding nameserver 208.67.222.222 from squid.conf
2013/02/07 12:17:57| helperOpenServers: Starting 15 'ncsa_auth' processes
2013/02/07 12:17:58| Unlinkd pipe opened on FD 26
2013/02/07 12:17:58| Swap maxSize 7680000 KB, estimated 590769 objects
2013/02/07 12:17:58| Target number of buckets: 29538
2013/02/07 12:17:58| Using 32768 Store buckets
2013/02/07 12:17:58| Max Mem  size: 262144 KB
2013/02/07 12:17:58| Max Swap size: 7680000 KB
2013/02/07 12:17:58| Rebuilding storage in /squidcache (DIRTY)
2013/02/07 12:17:58| Using Least Load store dir selection
2013/02/07 12:17:58| Current Directory is /usr/local/squid/sbin
2013/02/07 12:17:58| Loaded Icons.
2013/02/07 12:17:58| Accepting proxy HTTP connections at 127.0.0.1, port 8080, FD 28.
2013/02/07 12:17:58| WCCP Disabled.
2013/02/07 12:17:58| Ready to serve requests.
2013/02/07 12:17:58| Done reading /squidcache swaplog (0 entries)
2013/02/07 12:17:58| Finished rebuilding storage from disk.
2013/02/07 12:17:58|         0 Entries scanned
2013/02/07 12:17:58|         0 Invalid entries.
2013/02/07 12:17:58|         0 With invalid flags.
2013/02/07 12:17:58|         0 Objects loaded.
2013/02/07 12:17:58|         0 Objects expired.
2013/02/07 12:17:58|         0 Objects cancelled.
2013/02/07 12:17:58|         0 Duplicate URLs purged.
2013/02/07 12:17:58|         0 Swapfile clashes avoided.
2013/02/07 12:17:58|   Took 0.3 seconds (   0.0 objects/sec).
2013/02/07 12:17:58| Beginning Validation Procedure
2013/02/07 12:17:58|   Completed Validation Procedure
2013/02/07 12:17:58|   Validated 0 Entries
2013/02/07 12:17:58|   store_swap_size = 0k
Superato il limite di dimensione del file


Sadly the last (and probably more important) row is in italian and I'd translate it like "File size limit reached".

I've tried rebuilding cache but no luck...

What can I do?