Socks5 + implicit SSL causes infinite loop (100% cpu) on upload

[phicrew]

I thought it would be best to post in here before I open up a bug ticket because it just may be a user error with my settings.

Ok first off basic info:
client: FlashFXP 3.4 build 1145 unreg
OS: Windows XP Pro SP2 (with current updates)
Router: Linksys WRT54GS

[R] Connecting to (ftp-hostname) via Proxy -> IP=(socks5.proxy) PORT=1080
[R] SOCKS: Connecting to (ftp-hostname):6821
[R] SOCKS: Connected to (ftp-hostname):6821
[R] Connected to (ftp-hostname) via Proxy
[R] Connected. Negotiating SSL session..
[R] SSL negotiation successful...
[R] SSL encrypted session using cipher AES256-SHA (256 bits)
[R] 220 Gene6 FTP Server v3.9.0 (Build 2) ready...
[R] PBSZ 0
[R] 200 PBSZ=0
[R] USER testing
[R] 331 Password required for testing.
[R] PASS (hidden)
[R] 230 User testing logged in.
[R] SYST
[R] 215 UNIX Type: L8
[R] FEAT
[R] 211-Extensions supported:
[R]  AUTH TLS
[R]  CCC
[R]  CLNT
[R]  CPSV
[R]  EPRT
[R]  EPSV
[R]  MDTM
[R]  MFCT
[R]  MFMT
[R]  MLST type*;size*;create;modify*;
[R]  MODE Z
[R]  PASV
[R]  PBSZ
[R]  PROT
[R]  REST STREAM
[R]  SIZE
[R]  SSCN
[R]  TVFS
[R]  UTF8
[R]  XCRC "filename" SP EP
[R]  XMD5 "filename" SP EP
[R]  XSHA1 "filename" SP EP
[R] 211 End.
[R] CLNT FlashFXP 3.4.0.1145
[R] 200 Noted.
[R] CWD /projects/2007/04
[R] 250 CWD command successful. "/projects/2007/04" is current directory.
[R] PWD
[R] 257 "/projects/2007/04" is current directory.
[R] TYPE A
[R] 200 Type set to A.
[R] MODE Z
[R] 200 Mode Z ok.
[R] PROT P
[R] 200 PROT command successful.
[R] PASV
[R] 227 Entering Passive Mode (x,x,x,x,21,195)
[R] Opening data connection via Proxy
[R] SOCKS: Connecting to (ftp-ip):5571
[R] SOCKS: Connected to (ftp-ip):5571
[R] LIST -al
[R] Connected. Negotiating SSL session..
[R] 150 Data connection accepted from (socks5.proxy):2130; transfer starting.
[R] SSL negotiation successful...
[R] SSL encrypted session using cipher AES256-SHA (256 bits)
[R] 226-Compression : 27.07% (836 Bytes/3.016 KBytes).
[R] 226 Transfer ok.
[R] List Complete: 2 KB in 9.05 seconds (0.3 KB/s)
[R] TYPE I
[R] 200 Type set to I.
[R] PASV
[R] 227 Entering Passive Mode (x,x,x,x,121,72)
[R] Opening data connection via Proxy
[R] SOCKS: Connecting to (ftp-ip):31048
[R] SOCKS: Connected to (ftp-ip):31048
[R] STOR vc.project.test.zip
[R] Connected. Negotiating SSL session..
[R] 150 Data connection accepted from (socks5.proxy):2180; transfer starting for /projects/2007/04/vc.project.test.zip
[R] SSL negotiation successful...
[R] SSL encrypted session using cipher AES256-SHA (256 bits)

Once it reaches that point, it locks up and starts cycling 95-100% cpu usage.

I edited out the actual ftp and Socks5 proxy for my own privacy. I was able to upload the files to ftp ok with Filezilla but that client has issues with corrupting the uploaded data. If there is any more info I can provide, please let me know.

edit: I resolved it. I disabled Compression (MODE Z) for uploads. But I think this is a bug or some conflict with FTP? Program shouldn't be locking up.